


A Coct-Full of Kinks

by knowmeknot



Category: Undertale (Video Game)
Genre: Additional Tags In Chapters, BDSM, Begging, Body Swap, Bonds, Costume Kink, Crossdressing, Daddy Kink, Double Penetration, Ecto-Genitalia (Undertale), Forniphilia, Fucking Machines, Gags, Incest, Kinktober 2017, Lingerie, Medical Kink, Mind Control, Multi, Orgasm Denial, Prostitution, Role Reversal, Roleplay, Semi-Public Sex, Sensory Deprivation, Sex Toys, Shibari, Size Difference, Soul Sex, Stockings, Temperature Play, Tentacle Sex, Tentacles, Threesome, Wax Play, Xenophilia, lap dance
Language: English
Status: Completed
Published: 2017-10-01
Updated: 2017-11-18
Packaged: 2019-01-07 11:23:20
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 31
Words: 34,789
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12231822
Author URL: https://archiveofourown.org/users/knowmeknot/pseuds/knowmeknot
Summary: 1 day, 1 pairing, 1 or more kinks. These are my drabbles for Kinktober 2017. Full lineupHERE(NSFW).Noncon day 6.





	1. Sleepy Sex (US Papyrus x UT Sans)

**Author's Note:**

> **Additional tags: Ecto-penis, Frottage**

Stretch blinked awake to find himself lying on a ratty mattress with flimsy sheets. For a second, he thought there had been another Reset, and he’d been sent back to his universe. Then the lump known as Sans came into view, eliciting a soft sigh from his mouth. The petite — though still bigger than his brother — skeleton was still sleeping with his teeth slightly parted, soft snores filtering out. Drowsiness settled within Stretch, and a smile crossed his features.

He never would have imagined falling into a relationship with someone so similar to himself, but he and Sans bonded over shared experiences of the Resets, knowledge of alternative timelines, and love for their siblings. Perhaps it was the mix of having his Sans’s appearance along with his own personality that drew the two of them together.

It was a laid back, relatively stress free relationship, where he was able to act as lazy as he wanted. Granted, it worked that way for Sans as well. 

Said skeleton shifted and rolled forward right into Stretch’s chest. Blearily, Sans opened his eye sockets to half-mast, revealing hazy, white eye lights. He yawned.

“mornin’ sleeping beauty,” Stretch greeted.

He raised his left arm and curled it over Sans’s body to bring him closer, snuggling Sans like a teddy bear. A very bony teddy bear. 

Stretch could sense the faint hum of Sans’s soul vibrating gently in beat with his own. The sensation lulled him back to sleep when, suddenly, he felt languid strokes trailing along his sternum, making his bones tingle with warmth. Stretch peered down at Sans to find his sockets closed and his phalanges continuing their ministrations on their own accord. 

Stretch turned onto his right side and smirked as he pulled the small skeleton closer until Sans fit underneath his chin and their ribs practically slotted within each other, allowing his hands to reach under Sans’s white tank top to lightly caress his spine. Sans’s breath hitched in response, and he relaxed into Stretch’s brushes.

Closing his eyes and humming softly, Stretch worked his fingers through each of Sans’s vertebrae while Sans played with his ribs. It didn’t take long for him to wring a low moan from the smaller monster. 

Sans bucked their hips together. Pressure coiled within Stretch’s pelvis, allowing the magic there to coalesce into a long, hard shaft. Sans gasped when Stretch thrust his member against Sans’s pelvis.

“you gonna, ah, work me to the bone this mornin’?” A lazy grin stretched across Sans’s face.

“how ‘bout we both take it easy?”

He rutted against Sans again, this time feeling Sans’s thick cock through the track shorts that he wore to sleep. They moved back and forth against each other in a steady but slow motion. The sparks of pleasure caused by the friction had Stretch groaning.

Soon, both Stretch and Sans had discarded their pants. During a wide yawn, Sans used his tongue to lather his left hand in blue saliva, and grasped both of their dicks in his tiny hands, having to use both of them to account for their combined sizes. He smeared the liquid magic around both their lengths, squeezed them together, and rubbed them in a vacillating motion. Precum beaded the top of Stretch’s cock. Sans fingered the slit, sending shudders throughout his entire body.

Meanwhile, Stretch’s right hand, which had been fondling Sans’s spine, crept down to the back of Sans’s pelvis and swirled the shapeless magic there to form a puckered entrance. He inserted a phalanx into the soft flesh. Sans jolted.

“i _f-fingered_ ya were gonna go slower for how early it is,” Sans commented, and halted his movements. 

A low whine rumbled deep within Stretch’s throat at the lack of stimulation.

“at least be more _handy_ ,” he murmured in a low voice, inserting his finger deeper and wrenching a sharp gasp from Sans. “you gonna let me do all the work, kiddo?” 

“h-heh, don’t _kiddo_ -self, honey.” Immediately after Sans uttered the term of mocking endearment, he dipped down to lick sensually at the head of Stretch’s cock and pulled off. “can't have ya _cumming_ after me.” 

Stretch chuckled and caught Sans’s mouth in a kiss, moaning when he tasted his own magic on Sans’s wider tongue. He plunged his pointer in and out of Sans’s back entrance, feeling the muscle relax to accommodate for the size. Sans resumed playing with Stretch’s length, abandoning his own arousal. By this time, Stretch’s summoned flesh was slick with drool and precum.

He inserted a second finger, and Sans’s hole clenched tightly. Sans squirmed. Catching sight of the smaller monster's exposed clavicles, Stretch let his tongue dance lightly across the divots within each bone. Sans’s strokes grew more jerky and rough. 

Before long, both of them were panting softly. Arousal built up within Stretch, tugging at his core like an elastic band ready to snap.

“s-stop,” Stretch griped.

Sans stopped and gazed up at him, sockets lidded with desire. 

“that expression…” Stretch groaned. “you could say it really fires me up.

“well _water_ ya waitin’ for?”

Stretch rolled the two of them over on the bed so that Sans was on his hands and knees below him, pelvis in the air. Stretch crouched over the diminutive skeleton, and pressed his throbbing dick into Sans’s asshole. Sans was loose enough and his length was slick enough for him to easily slide in. He bottomed out, moaning.

“this feels amazin’, sans.”

He remained still, soaking in the bliss of Sans channel wrapped perfectly around his member, eyes closed. He could probably fall back asleep like this. A whine snapped him out of his trance.

“ _cum-on_ , move if ya don't want me to pass out.”

Stretch chuckled. He pulled out and drove back in, setting a rhythmic pace. The clacking of bone and their moans filled the room. The lewd sounds worked hard to spur him on. Temporarily at least.

Unfortunately, this was simply giving him too much of a workout so early in the morning.

Stretch yawned. 

And fell asleep mid-thrust.

Several minutes ticked by before Sans shifted from his pinned position beneath the other.

“stretch... buddy?”

No answer.

“honey _bun_?” Sans snickered and wiggled his butt with Stretch’s cock still buried deep inside.

A snore greeted him.

Sans huffed, “welp. guess that's it then.”

He’d been in far more uncomfortable positions while sleeping so it didn’t take him long to join his _bonefriend_ in slumber.


	2. Forniphilia (SF Sans x UF Sans)

**Summary for the Chapter:**

> In which Razz treats Red like a fine piece of furniture.

**Notes for the Chapter:**

> **Additional tags: BDSM, bondage, blindfold, ecto-vagina, ecto-penis, pain play, orgasm denial**

Red found himself in a very compromising position, precipitated by several factors. One, he was completely naked, and his bones rattled as the cold air blanketed him. Two, he only saw darkness; he had been blindfolded. And three, he was kneeling. It was not by choice. 

Thick, nylon robes bound his femurs to his tibia and fibula and snaked in between the crevices between each individual vertebrae, forcing his back into an upright position. His forearms were tied together and secured behind him, tethered to his spine. Two lengths of rope connected each of his humeri to his ankles, limiting movement in those limbs. Thick, silk ribbons also weaved through his ribs in what seemed to be a criss-cross pattern along his sternum. 

The bindings were so tight that, when he tried shifting his position, he couldn’t. At all. It only shifted the ribbons threaded through the spaces between his ribs, rubbing them against both sides of his sternum. He shivered.

He heard the sharp click of heels in front of him, and lifted his skull to the sound. There was only one monster who wore boots with heels.

His partner and dom.

“r-razz?”

A hitch arose within Red’s throat as pointed phalanges flitted down his ribs, tugging on the silk ribbons. Unformed magic quickly pooled within his exposed pelvis.

“WELL, WELL, RED, NOW THE MAGNIFICENT AND MERCILESS SANS HAS YOU IN HIS CLUTCHES!” Smug satisfaction dripped from Razz’s tone.

A claw fondled Red’s pelvis, swirling the magic there. It was rough and left him breathless. Razz molded the magic into a short, but thick erection. Red’s tongue soon materialized within his mouth.

“MWEH HEH, NOW HOW SHOULD I PUNISH YOU FOR YOU MISBEHAVIOR TWO DAYS AGO?”

“whatever d’ya mean, sir shrimp,” Red couldn’t help but taunt.

He knew his words would lead to him for a painful evening. But this was the type of relationship they had and he sought out. The whole reason he’d ended up in this situation, after all, was due to his calling Razz “a pipsqueak” two days ago on their date to the planetarium. It was a term Razz absolutely abhorred and was guaranteed to lead to the type of harsh punishment that Red craved. 

“IT SEEMS I HAVE FAILED IN MY TRAINING OF YOU, MUTT!” Razz snarled.

Red sensed the crackling vibration of magic. 

Pain exploded at his groin as a heel stomped down hard at his engorged length. A half scream, half moan flew out from his sharp teeth, as his tongue flopped out of his mouth. 

The painful pressure on his member suddenly vanished. Red could hear the sound of Razz marching away. 

Razz wasn’t gonna just leave him helpless like this, was he? Red’s breathing became more ragged at the thought.

Seconds later, Razz came back to where he was positioned on the floor and slipped a ring around his ecto-penis. Red whined at the squeezing discomfort.

“PERFECT! CHAIRS DO NOT LEAK FLUIDS.” Razz’s higher-pitch voice was bright, though it contained a hint of dangerous anticipation. “NOW I SHALL USE YOU AS I SEE FIT!”

Red moaned and panted like a bitch in heat at Razz’s words, lust bursting through him. Just the idea of the other using him like a piece of furniture stimulated his masochistic tendencies and set his magic alight. 

He could come right now if he wanted to. Not that he could.

“SAFE WORD?”

“reset.” 

Razz gave a noise of confirmation.

The blindfold came off, revealing the smaller skeleton to be completely bare except for his knee-length black boots. Purple ecto-flesh filled in the spaces that were originally bare bones, and a glistening mound glowed between Razz’s thick but toned upper thighs. Red’s mouth watered at the sight, the saliva dribbling down his chin. 

Razz, despite how petite he was, appeared imposing as he straddled on top of Red’s femurs and sat down, grasping the ribbons decorating Red’s ribs. He spread his curvy legs farther apart and curled them around Red so that his soft folds brushed against the head of Red’s cock. 

Red whimpered and tried to squirmed for more stimulation, only resulting in pulling the ribbons around his ribcage taut. Razz dragged his claws across Red’s various bones, deep enough to draw marrow. Red keened and his eyelids fluttered, already reaching his peak. The pressure mounting in his arousal became unbearable. 

“h-hah... lemme come!”

He received a loud slap in response; the force of the blow jerked his head to the right and drew scratch marks. 

“FURNITURE DO NOT SPEAK!” Razz barked. “REMAIN SILENT OR I WILL GAG YOU!”

Red was tempted to utter another snide remark, but instantly threw away the notion once Razz’s wet ecto-vagina teased the tip of his dick. It throbbed painfully with the cock ring around it. Razz’s cheekbones were a deep purple, and his groans echoed throughout the room.

Red felt ready to burst if this foreplay continued any longer; he needed the other’s tight pussy around him. But he knew Razz would not grant him his release so soon without torturing him first. 

Then, without warning, Razz sank down on his dick. Red couldn’t stop his cry of pleasure. Another smack greeted his cheek left.

“WHAT DID I SAY?”

The stinging pain on his face coupled with the delicious heat of Razz’s soft channel sent him over the edge. Too bad he couldn’t come. 

Razz rode him at a furious pace with his spine arched into Red, who no longer cared what lewd noises were coming out of his mouth. Razz had an expression of absolute bliss. Moans and the wet squelch of his summoned flesh sliding into Razz’s pussy filled the room. Razz rubbed the nub at the top of his slit with his thumb, and he came with a violent shudder. Purple magic coated Red’s member, some of it leaking onto his femurs. Without acknowledging Red’s tight, pre _dick_ ament, the other started again. 

Razz climaxed two more times before he finally removed the cock ring from Red’s erection. As soon as he did, red cum spattered all over Red’s ribs and femurs, some of it even landing on Razz’s front. Red came long and hard, so much that stars lined his vision. Once he was finally done, Razz wiped the liquid magic away with a look of mock disgust. 

“DIRTY FURNITURE MUST BE WASHED; HOWEVER, IT WOULD BE A WASTE OF WATER TO CLEAN YOU SO SOON,” he declared. “PERHAPS AFTER USING YOU SOME MORE, I WILL THINK ABOUT CLEANING YOU.”

Red wailed as the other skeleton impaled himself back on his length and started anew. 

It was gonna be a long (but thrilling) night.


	3. (Semi-)Public (soul) Sex (Nicepants)

**Summary for the Chapter:**

> Semi-public, long distance soul sex featuring a pair of NicePants

**Notes for the Chapter:**

> **Additional warnings: none**

Nice Cream Guy carefully massaged the tiny, pearlescent heart cupped within his furry blue paws. He was currently manning his nice cream cart in Hotland, located on the side and in front of the entrance into the MTT Resort. Feeling rather bold, he would bring it out in the open when nobody was around, would stroke the soul, and then quickly hide it as monsters drew closer to him. 

After all, it was indecent to reveal a monster’s soul unless it was for battle or intimacy. This fell squarely within the second category. 

A mingle of fear, arousal and excitement emanated from the mysterious core. Nice pressed the pads of his right pointer at the center and was met with a squishy, squelching sound as fluid began to drip from the inverted, heart-shaped organ. 

He only wished he could see all the various and delicious expressions his boyfriend was making during his ministrations. No doubt his partner was having, as Sans would say, a “good time”. 

Speaking of the short skeleton, he suddenly appeared in front of the wall of the building, as though he’d walked straight through it like a door. Nice immediately shoved the soul into the breast pocket of his uniform. Having the soul so close to his own filled with him such warmth that he hummed.

“you enjoyin’ yourself there, nice?” Sans leered, his eye lights briefly stopping at the pocket hiding the soul.

“Ahaha, n-not at all. Just happy with g-good business!” he stuttered in response.

“well don’t mind me. i’ll be _soul_ ly alone.” 

Sans winked and then sauntered to the other side of the MTT Resort entrance.

Nice sighed in relief — that had been a close call — and took the soul back out. He noted that there was a distinct damp spot on his shirt. 

Before he could continue, a short bipedal monster wearing a blue and purple striped shirt with brown hair and yellow skin approached him. Nice quickly hid the sacred object behind the open glass of his cart. The cool air rushing out caused the soul to quiver violently, and it flashed brightly as though it were a disco ball. Nice swiftly covered it with his hand so the child wouldn’t see. They pointed at his cart.

“Sorry, I’m all out of nice cream. Those Royal Guards bought my last ones. Maybe try the MTT Resort?”

The child tilted their head, regarding him with suspicion before sighting Sans. They ran towards the blue-clad skeleton, leaving Nice Cream Guy to himself once again. He peered around, and after spotting no nearby monsters, he twisted the tip of the soul, causing liquid magic to soak into his fingers like water in a wet rag. 

It almost resembled a melting nice cream bar. Should he lick it?

\-----

Burgerpants suppressed a groan as he felt the loving intent pour into him via his soul… which was currently in Nice’s hands, located outside the MTT Resort. He squirmed behind the counter of the MTT-Burger Emporium and attempted to keep his eyes from closing in bliss. This only resulted in monsters giving him strange stares. 

Thank God Mettaton didn’t seem to be working today. What would his boss think? 

No doubt he would broadcast it for the whole Underground to see. It would be a scandal for the century.

Maybe he deserved it for being so stupid as to agree to this in the first place. Though, he couldn’t stop the excitement at the thought of getting caught.

Burgerpants gasped when warmth flooded him. Wherever Nice was keeping his soul, it must’ve been close to the rabbit monster’s own. The strum of their magic resonated together. His face scrunched together with his left eye twitching violently. 

After the initial shock of being so close to Nice’s soul tapered off, Burgerpants managed to keep his features neutral... Until coldness seeped into his very core. It was like opening a freezer and taking a full blast of cold air. Except at the most important and sensitive part of him. He clenched down on his teeth to stop any embarrassing sounds from leaving his mouth, and jammed his right hand into his pocket to reach for a cigarette.

When the urge to climax finally passed, he found himself staring at a short monster child wearing a blue and purple striped shirt with brown hair and yellow skin. They squinted up at him.

Burgerpants took a brief smoke of his cigarette to calm down and then attempted a welcoming smile.

“Welcome to MTT-Brand Burger Emporium, home of the Glamburger. Sparkle up your day.” His ears flattened as another wave of pleasure hit him. “What can I do for you, little buddy?”

The child continued their gaze and slowly lifted an arm to point in the direction of the exit.

Burgerpants cringed. “What? Why do you keep trying to talk to me? I'll get in trouble if I get chummy with the customers. Sorry.”

They kept pointing at the outside of building, and then made rabbit ear gestures with their hands.

Without warning, something soft and wet touched his soul. His perseverance finally failed him; his orange fur stood on its ends as a loud moan escaped his mouth. His eyes closed as he arched into the counter..

When he opened them again, the monster in the striped shirt gaped at him with their mouth in an O. Sweat poured down Burgerpant’s face as realization of what had just happened dawned on him.

He’d climaxed in front of a monster child!

He gave a strained grin, eyebrows twitching like caterpillars. “Listen. I like you, little buddy. So I'm gonna save you a lot of trouble. Never interact with attractive people.”

The child regarded him with confusion for several seconds. Then, they directed two finger guns at him while suggestively waggling their eyebrows, and walked away.

The gesture caught him completely off-guard, but he decided to let it go. It was too much effort to worry about it now that it’d passed. He was in the clear. Or was he?

As though the universe hated him, a familiar and smooth “Oh my!~” came from behind him. Perspiration dotted his forehead even more as he slowly turned around. 

Mettaton stood in front of the door into the CORE with a knowing smirk on his lips.

Burgerpants slapped his paw into his face and muttered, “This is hell.”


	4. Begging (Grillster)

**Summary for the Chapter:**

> Gaster completes a contract with Grillby to become his summoner after begging for it.

**Notes for the Chapter:**

> This prompt plays with the idea that fire monsters are elementals that have to be summoned to be part of the world, and without a summoner, they would die. This is actually pretty safe for work, and I really stretched the "begging" part of this prompt.
> 
>   **Additional warnings: none**

W. D. Gaster sighed as he stood on the desolated battlefield. Dead trees stood in the barren landscape, their gnarled branches twisted like a witch’s claw. Monster dust clung so heavily in the air that even taking a single breath felt as though he was smoldered in it. They had suffered such a terrible loss against the humans that King Asgore had ordered all monsters to retreat.

There was no doubt in Gaster’s mind that the monsters were closed to finished; they could only last one more battle. The humans have already won.

Gaster took one final sweep around him, and was startled when something flashed red in the distance. He took off in the direction of the flickering light. As he drew near, Gaster saw that it was a ball of fire a third the size of his body.

It was a flame elemental. These species of monsters were powerful but highly dependent on their summoner for their continual existence. A pile of dust lay in a scattered pile amongst the gray grass. The dwindling embers struggled to stay lit. 

Gaster’s eye sockets widened when he heard a deep, crackling voice beg, “Please… help me… keep me alive!”

An urge overcame Gaster to help the dying monster after hearing his plea and seeing his relentless struggle. Gaster summoned a lengthy purple construct shaped like a femur and stabbed it directly into the ember’s core. The surprising move nearly extinguished what was left of the flame.

Then, without warning, it sparkled into a formless bonfire, as Gaster poured his perseverance magic into the other monster’s core. The blaze expanded rapidly into a vaguely humanoid shape and transformed to a brilliant orange and yellow color. Eventually, the fire solidified into a kneeling position.

“... Thank you… I owe my life... to you,” the same voice from earlier said. 

“It is no problem. We are all monsters after all.”

He lifted the bone to remove it from the flame elemental when it refused to budge. Flames wreathed around the femur, held fast by the incorporeal being.

“I need… a new summoner to survive… please… become my new master.”

Gaster raised his arm and used his left hand to stroke his chin thoughtfully. He’d never thought about having a monster around like an elemental. It would definitely offer him protection. His scientific mind already thought of ways he could test the differences between their magic, stats and endurance. Plus, Gaster had to admit the monster was quite… -i-hot. He chuckled at his own joke.

Maybe the two of them could keep each other company. Although he was highly regarded by and was a friend of Asgore, to have a companion would be nice.

“I will do it,” he agreed. “Would sharing magic be the easier method?” 

Sharing magic was the swiftest and easiest way to gain control of the flame elemental. 

“Yes… that would work best.”

Without any further hesitation, Gaster bent down and pressed his mouth against the embers that resembled a head while simultaneously sinking the purple bone further into the other. The elemental crackled loudly and turned a brilliant shade of blue; they burned hotter.

It was an interesting experience, kissing fire, but Gaster allowed himself to get caught up in the warm passion for a good minute. The monster strengthened, and he pulled away.

“...No… k-keep going… please… master.”

Gaster’s soul swelled and fluttered at the monster’s pleading tone. Perhaps this was his weakness. He immediately continued their “kiss” and pulled the elemental flushed against his chest. The magic within their souls collided together. Heat crashed in waves throughout Gaster’s entire body.

Orange. The color of bravery, mingled with his purple. 

The other’s flames lost their shape from the intensity of their magic transfer. It didn't take long for an explosion of orange and violet filled the area around them. As Gaster came down from his high, he noted that his soul had spots of orange within its - the resummon was complete. Only one final step remained.

“Do you have a name for me to call you?”

“No, master.”

Gaster shook his head, “It is not necessary to call me ‘master’. I am W. D. Gaster, and from now on, you may address me as simply Gaster.”

“Yes… Thank you.”

“My name for you,” Gaster smiled broadly, nearly splitting his face, “from now on, will be… Grillby.”


	5. Body Swap (Undyne x Alphys x Papyrus)

**Summary for the Chapter:**

> Undyne and Papyrus accidentally take a body swap potion. Shenanigans ensue.

**Notes for the Chapter:**

> **Additional warnings: vaginal fingering, sensitive bones**

“C’mon Papyrus, pound that tomato to submission!” Undyne roared. She stood to the left of him, striking her fist against the kitchen counter.

She and Papyrus had decided to have a friend-date since Alphys was still away at a work-related conference, and Sans was chaperoning a school trip on behalf of Toriel’s class. The two had always got along like oil to a fire, their passions equally bright. It made them easy to get along - a relationship stronger than (best) friends yet weaker than siblings. If Alphys hadn’t caught her one good eye, then maybe their relationship could’ve developed into something more.

“YES, WE WILL BEAT THIS INTO SUBMISSION!”

Papyrus gave up attempting to cut the tomato and smashed a gloved fist into the red vegetable (or was it a fruit?). Its crimson juices, sprinkled with seeds, splattered onto the counter, some of it sticking to the tiled wall. 

Undyne helped dump all the ingredients into a small pot. Papyrus was about to turn on the heat when Undyne stopped him, and held up a thin vial of pink liquid.

“We should put some of this stuff into it!” Undyne suggested, giving a toothy grin.

“WHAT IS IT? WILL IT MAKE OUR FRIENDSHIP SPAGHETTI TASTE BAD?”

“No, way, Paps! This stuff was made by my awesome girlfriend. I’m sure it’ll be great!”

“THEN LET’S ADD IT ALL!”

“Yeah!”

Undyne carelessly dumped the contents of the vial into the simmering tomato sauce. Before long, two steaming plates of spaghetti sat on the kitchen table. They both wolfed down the food, both competing to see who would finish first. Afterwards, they spent the rest of the evening watching stimulating (for Papyrus) action movies until they both decided to call it a night.

 

The next morning, Undyne woke up in a red racecar bed. Not only was that not her bed, but the room wasn’t hers either. Action figures stood on a shelf along the back wall, adjacent to a wooden desk that had a computer set on it. This wasn’t her room it was... 

“WHAT THE HELL?!” she hollered in horror as she realized her normally blue, scaly body had been replaced entirely of bone! 

She sprang right out of the bed. 

_Bang!_

The door slapped against the walls, and nearly snapped off their hinges. Instead of the yellow and purple wallpaper that decorated her and Alphys’s house, there was a poster of a large bone against green walls. This was Papyrus and Sans’s house, which only confirmed her fears.

She was, somehow, in Papyrus’s body, which likely meant that he was currently inhabited her body as well.

If Papyrus inhabited her body, what could possibly go wrong? Especially when Alphys would be home early this morning. Undyne knew from experience that her girlfriend was extra horny after spending more than a day without being in close proximity to Undyne. 

With those thoughts at the forefront of her mind, Undyne ran out of the house towards her own. It was a good thing they lived within the same neighborhood.

\-----

Papyrus was in a truly puzzling situation; he’d somehow woken up next to Alphys. The small lizard scientist, thankfully, had been asleep, muttering indecipherable words in whatever dream she was having. Papyrus shifted to get up, but was immediately trapped when Alphys rolled over and wrapped her arms around him.

That was when he saw the flesh and blue scales covering over his bones.

“AHH!”

Papyrus exclamation startled Alphys awake, who tightened her embrace around him. The squishiness of flesh touching flesh - he was only familiar with bone against flesh or bone against bone - felt nice. It was definitely something different. A few seconds passed, while she took a deep breath, and peered at him.

“Undyne? Y-you alright?”

How had he somehow ended up in Undyne’s body? 

“I’m fine! I was simply caught by surprise!” 

Alphys blinked and squinted at him. Then she gave a lewd smile.

“Per-perhaps I can fix that… with. a. kissu~” Alphys giggled. 

She suddenly loomed on top of Papyrus, who fell back against the bed in shock. Just as Alphys was about to kiss him, the door to the bedroom slammed opened. Papyrus loomed in the doorway.

“DO NOT KISS THAT UNDYNE!” Papyrus heard himself shout. “THAT IS NOT ME!”

Alphys pulled away as if burned.

“THAT ME RIGHT THERE IS PAPYRUS! I AM UNDYNE!” She charged onto the bed. 

A pair of bony arms picked up the lizard monster, grasped her chin lightly with one gloved hand and pressed a pair of bony teeth against fleshy lips. Although Alphys’s eyes widened dramatically, she eventually leaned into “Undyne”. She even swiped her tongue against the pearly, skeletal teeth.

A tightening pressure coiled within Papyrus, and he felt heat rise into “his” face.

It was very attractive, seeing himself making out with Alphys. He was simply so great that he paired well with anyone! Hearing himself moan so obscenely was even more startling, in a good way.

Eventually, Alphys pulled away, panting slightly, and cheeks flushed red. 

“H-how did this h-happen, Undyne? W-why are you in Pa-papyrus’s body?”

Papyrus thought back to their friend-date yesterday and remembered the pink concoction Undyne had poured in there.

“Could it have been that liquid you put in the spaghetti sauce, Undyne?” He asked in his normal, boisterous tone.

Alphys squealed and clutched at her face. “You did WHAT?! And how much did you put?!”

“ALL OF IT! YOU SAID IT WAS GONNA HAVE AN AWESOME EFFECT, WHY WOULDN’T I PUT ALL OF IT FOR MAXIMUM AWESOMENESS?”

“B-b-but!” Alphys sputtered, her eyebrows twitching viciously. “It's a soul-body swap potion. Your soul is currently inhabiting Papyrus’s body while he’s in yours.”

Dead silence filled the room. It was quiet enough that a pin drop could be heard.

“SO HOW DO WE SWITCH BACK?”

Scarlet dusted Alphy’s entire face as she mumbled, “Just like in that one anime we watched a month ago... y-you kiss the other to switch back.”

Alphys buried her face in her hand in embarrassment. “Undyne” faced him.

“ALL RIGHT PAPYRUS, LET’S KISS AND FIX THIS MESS.”

Papyrus hesitated and then asked, “I have never been in a fleshy body before. Do you mind if we… Um… Experiment.”

“I d-d-don’t mind,” Alphys mumbled. “If you don't, Undyne. I-it's still y-your body.”

“I’ll give you permission to fondle my lovely bones, Undyne!”

“Undyne” took a minute to think about it before she gave a thumbs up. Alphys swiftly closed the distance between them on the bed, grabbed ahold of one of the flesh lumps hanging off his chest — he’d heard them being called “breasts” — and kneaded it. Papyrus let out a startled yelp as pleasure filled him. He rocked into Alphys’s bold ministrations. 

“GEEZ, ALPH, WATCHING YOU PLAY WITH MY BOOBS IS SO HOT.” 

A moan escaped Papyrus’s mouth as she twirled the perked flesh at the end of the breast. From the corner of his eyes, Papyrus saw that Undyne was stroking certain bones in his body.

“A-ah! Come closer, Undyne,” Papyrus gasped. He lifted an arm. “I shall show you my pleasure centers!”

As soon as she was close, Papyrus fondled his own ribs, ripping a strangled gasp out of his best friend. Watching himself through lidded eyes, Papyrus couldn't help but think how handsome of a skeleton he looked while aroused.

Undyne used “her” phalanges to trail down Alphy’s upper thighs, wrenching a unabashed moan from the lizard monster.

Eventually, soft lips press against his own. Papyrus hummed against it while his hands drifted to his own spine. Loud pants and groans bounced off the walls of the room. His kiss with Alphys broke apart, and Undyne then claimed her mouth. 

A hand slipped into the pajama pants that Undyne wore, and the pressure coiling with Papyrus’s core exploded. Deft fingers grazed against the soft, puffy slit in the groin of the body he currently inhabited. It was like nothing he’d ever felt before, causing shivers to wrack his frame. 

In turn, Papyrus dug his digits deeper between the spaces in his vertebrae, working down to the pelvis bone. The scaly hand ghosted over the holes along his sacrum, and then pinched his coccyx. Undyne clenched at the bed sheets so hard as she came that it ripped holes in them. A flash of orange, coming from his ribcage, burst into the room.

Papyrus screamed and arched his back as a finger slipped in and out of the wet slit, and a thumb rubbed circles against the nub at the top. He felt his inside explode in pleasure, and liquid gushed from the slit that Alphys had been stimulating. At the same time, her face scrunched up in absolute bliss as she wailed loudly.

All three of them panted deeply as they came down from the pleasant buzz. 

After a few minutes, Undyne asked him, “READY TO SWITCH BACK”

“Yes!”

They turned to each other. His own bony teeth pressed against the soft flesh of Undyne’s lips. At first, there was nothing. Then, a brilliant flash of white light enveloped the room. When if faded, Papyrus saw that he was back in his own skeletal body. 

“WHAT A DELIGHTFUL EXPERIENCE! THANK YOU BOTH FOR GIVING THE GREAT PAPYRUS THIS OPPORTUNITY!.”

“Heh, no problem Paps. Hey, if you and Alphys agree to it, we can do it again.”

They all agreed.


	6. Size Difference and Bonds (**UF Asgore x UF Sans)

**Summary for the Chapter:**

> Sans finds a job, and it required much more than he bargained for.

**Notes for the Chapter:**

> This drabble uses the headcannon that as a king’s judge, the boss monster has a huge influence on their actions (aka almost mind control). Also, please heed the warnings cuz this one's a doozy. You've been warned.
> 
> **Additional warnings: Rape/Non-con, manipulation, mind control, mind break, skull-fucking, non-consensual soul bond, attempted oral**

Sans grumbled as he wandered throughout the dreary, winding streets of New Home. Random piles of dust varying in different sizes passed his view. He was only in this wretched city to find a job. Hopefully that would finally get Papyrus to stop harping on his laziness. They’d gotten into another violent argument over it again; and this time, Papyrus wouldn’t let him go back to the house until he found a job.

What did Papyrus know? It wasn’t as though Sans purposely acted lazy. He simply found it difficult to find a suitable job given his dismal stats. No Royal Guard was going to hire a monster with 1 HP. He was a joke, with monsters calling him “dead on arrival” in their kill or be killed world. He did have one skill that no one knew about - not even his own brother.

Ever since he and Papyrus had escaped from the late Royal Scientist’s clutches, he’d somehow gained the ability to clearly see a monster’s LOVE. Not only that, his attacks also seemed to do way more damage than his poor stats implied. It mimicked a poison-type of effect that gradually reduced a monster’s HP over time until they dusted.

Either way, Sans hoped King Asgore would hire him for whatever “special job” the boss monster had been advertising. However, when he reached the entrance to the castle, the Royal Guards immediately blocked his path. 

“State your reason for seeing the king, runt!”

“imma hopin’ to work fer the king.”

The two guards blinked and stared at each other, before turning back to him and laughing as though they’d just heard the funniest joke.

“Sorry, punk, I’m afraid you aren’t qualified enough for the job.”

Sans bared his razor-sharp teeth and snarled, “that ain’t fair! it said anyone can interview fer it!”

Both guard members lifted their spear and pointed it at him. Sans checked their stats to find that both monster had a LOVE of 12. As they attacked with arrow bullets, Sans leapt to his right and retaliated with a row of sharp bones. Two hits reduced the guards’ HP down to the single digits. 

“Why you little shit! Die!”

More bullets shimmered in the air around him. Before the guard's attacks landed, a glowing, crimson trident pierced through the guard’s chest.

“Gah!” was all he uttered, and then he became dust.

The dark, imposing figure of their King stood in the entranceway, his pitch-black armor seemed to absorb any light that hit it. He was triple the height and doubled the size of Sans. Asgore’s beady eyes glared at the remaining Royal Guard. A strange, imposing power eluded off of Asgore in waves that Sans became inexplicably drawn to.

“Leave us be or you will suffer the same fate as the other.” 

The threat underlying Asgore’s tone didn’t leave any room for discussion, and the guard fled the scene. With now just the two of them, the boss monster turned his attention to him. Sans’s soul flutter and tighten in response.

“What is your name?”

Sans, never one for manners or proper etiquette, simply held out a bony hand and blurted, “sans.”

He frowned. He’d never answered a question so readily and truthfully.

Asgore stared at the offered hand, and then gazed directly at his face.

“You are quite bold, I see. Are you not going to kneel before your king?”

As if a great pressure settled on top of him, Sans immediately sank down onto one knee and bowed his head. 

“sorry.”

The King’s mouth curled upwards into a snide smile and nodded.

“Your language will need some work, but all in good time. Well, Sans the skeleton, you have now been appointed as my Judge.”

As soon as those words left Asgore’s mouth, Sans’s mind blanked out, the sensation similar to filling his skull with balls of cotton. The next thing he knew, he was following after Asgore as the boss monster gave a tour of his palace. It all occurred in a blur. On the way out, he haphazardly mentioned his situation of Papyrus not letting him home until he found a job. 

“You are welcome to spend the night here. There are a few guest rooms available.”

Asgore placed a paw on Sans’s shoulder; it nearly covered his entire right chest. Asgore’s touch lingered and trailed down his back, sending shivers down his spine.

“Am I acting too forward?” Asgore asked.

Sans knew something was off about this situation, and he should be resisting more, but his fight or flight instincts seemed to have been suppressed. In fact, Asgore’s increasingly suggestive strokes had reached his lower spine. Sans finally had the mind to break away from the giant goat-like monster.

With a moment of clarity, he rudely declined the offer and took a shortcut back to Snowdin as soon as he was out of Asgore’s sight. Sans didn’t understand what came over him to allow Asgore to touch him like he’d done. 

When he got to his and his brother’s shared house, he’d expected Papyrus to welcome him with excitement and pride for obtaining such a prodigious job like becoming the King’s judge; instead, when he told his brother of the good news, Papyrus scowled at him with his arms crossed.

“LIES WILL NOT GET YOU BACK HOME, WHELP!” His crimson eye lights narrowed into slits. “YOU EXPECT ME TO BELIEVE SOMEONE OF YOUR CAPABILITIES WOULD BECOME KING ASGORE’S JUDGE? DON’T MAKE ME LAUGH!”

Sans flinched back as if struck. “what the fuck, boss? ‘m tellin’ the truth! why would i lie ‘bout this?!”

“ARGH! DON’T COME BACK UNTIL YOU FIND A REAL JOB!”

And like that, Sans was left standing at his doorsteps. After the initial shock faded away, he ended up shortcutting back to New Home, and took up Asgore’s earlier offer. 

“s’fine if i stayed in a guest room,” he mumbled.

Asgore led him to a room that appeared to have been the late Prince Asriel’s. He sank into the bed and fell asleep.

 

For the next two days, Sans remained at the palace and worked under Asgore, judging various monsters for their crimes. His ability to read souls made it hard for lies to sneak past him, decreasing the hours of time Asgore normally spent on evaluating citizen behavior. He found it unjust that certain monsters were executed even for the most minor offenses, though he never had the desire or need to go against the king.

In between these judging sessions, Asgore caressed Sans with increasing boldness, to the point where the king’s grazes would reach his clothed pelvis or lower spine. And no matter how wrong and uncomfortable it was, Sans found it seemingly impossible to disobey Asgore. His mind felt like it was in constant fog, and the longer he stayed in the boss monster’s proximity, the denser the fog became.

Then on the fourth day, Asgore insisted that he spend the night with him. And he’d agreed with barely a moment’s hesitation. As Sans lay on the enormous bed, his tiny frame not even taking up a third of it, soft fur grazed over his chest.

“You will allow an old monster like me to indulge a bit, won’t you?” the King intoned, his dark eyes boring into Sans.

“n—yes.”

Asgore positively beamed, and sank his paw under Sans’s shirt and fondled his ribs. The goat monster’s hand nearly covered his entire ribcage. Sans quivered in equal amount of pleasure and disgust at Asgore’s inappropriate ministrations. Heat and magic rushed up into his face. It didn’t take long for his heavy pants to fill the room. 

A shameful whine escaped Sans’s maw when the touches stopped. He lifted his skull to see Asgore unbuckling his belt and removing his pants. His gigantic, hairy dick sprang free. Sans watched through lidded sockets as Asgore pumped his erection several times until beads of precum leaked from the top. He then placed a paw on the back of Sans’s head and pushed it towards his engorged penis.

“Finish me off,” the King ordered.

Why wasn’t he fighting back? He should… **fight back**! There was no way something this long and thick would fit in his mouth. 

The fog cleared briefly, and he gained enough of his mind to croak back, “n-no, s-stop!”

But Asgore wasn’t taking that as an answer. He seized Sans’s lower jaw, wrenched it open, and shoved his massive length as much as it would go into Sans’s mouth; it didn’t even reach halfway. Sans gagged and squirmed to get it out. Tears beaded the corner of his sockets from the aching discomfort, and saliva dribbled down his chin. Bushy fur revoltingly tickled the insides of his jaws, and the smell of musk filled his senses. 

After Asgore’s attempting to thrust into his mouth had failed, the boss monster finally pulled out. Sans gasped and hiccuped from the relief. Loud rattling bounced off the walls of the room due to how much he was trembling. Asgore glowered down at him.

“Perhaps my influences on you are not deep enough.” A terrible smirk flashed across his shaggy features. “That can be rectified.”

Without warning, Asgore pinned Sans’s back down onto the bed, crouched over him, and plunged his dick into Sans’s left eye socket. 

Sans screamed. 

Asgore pulled out and thrusted back in, repeating the motion rhythmically. Spiderweb cracks grew along the rim of Sans’s left socket, and a jagged one appeared down the left side of Sans’s head, reaching down to his cheek. Tears poured down his face as he wailed at the constant agony.

“If I bond with you, you will truly become my Judge.”

Despite the haze of pain and growing numbness of everything that was happening, Sans still felt the tug at his soul. He sobbed and struggled as much as he could against the penis that repeated stabbed into the pool of magic located in the back of his head. He didn’t care if it tore half of his skull opened; as long as Asgore didn’t bond with him, he could still be salvaged. 

It proved to be futile.

Sans’s soul shined yellow in the air while Asgore’s gleamed the red of Determination. As soon as they were brought together, all the fight fled out of him, and he sank limply into the bed like a puppet with its strings cut.

His mind shattered.

 

Sans stood in the dust-covered corridor of the Judgment Hall. Gray mist hung in the air, obscuring the normally golden hallway. He had been ordered by his king to eliminate all the members of the coupe trying to overthrow Asgore’s unjust rule. The leader of the group was none other than former captain of the Royal Guards, Undyne.

But the fish monster never came. Instead, a tall skeleton clothed in black armor and a tattered red scarf stepped into the hallway.

“SANS?! YOU’RE ALIVE?!” the skeleton gasped in disbelief, and tears dotted the corners of his eyes. “I WANT TO APOLOGIZE FOR HOW I’D ACTED! I MISSED YOU, BROTHER!”

Brother…?

The monster in front of him was so familiar, yet Sans could not connect the dots of who this was. Besides, it did not matter. 

He had an order to fulfill as the Judge to his King.

**Notes for the Chapter:**

> This may or may not have a continuation as an actual fic someday... maybe. It would be focused more on Sans's recovery though if I do decide to write it.


	7. Crossdressing and Creampie (Papyton)

**Summary for the Chapter:**

> At a costume party, Papyrus's costume sets a spark within Mettaton.

**Notes for the Chapter:**

> **Additional warnings: ecto-vagina, ecto-thighs, vaginal fingering, penetration**

Life on the surface was simply wonderful. With his masterful acting abilities, Mettaton had become renown among the humans, and he absolutely loved the attention. It didn’t help he also threw the best parties neither human nor monster could argue against. He was, as people would call, the star of the party. Being an attractive robot definitely helped as well, since there was a certain sector of humans that loved the idea of sexing a robot.

This changed when Papyrus became his boyfriend, or “bonefriend” as Sans would call him — the term made Mettaton’s eye roll. With Papyrus’s illuminating personality, the two of them tried to outshined each other, but both ended up becoming better and more brilliant. And tonight’s annual Halloween Costume Party was definitely a good example of that.

He had dressed up as a vampire. He wore a three-piece suit consisting of a button-down black vest, white undershirt, black pants and a red banded decorative amulet. A silky bi-colored cape fluttered elegantly behind him as he walked. The inside was red while the outside was as black as night. His polished shoes glinted in the dim lighting.

Despite his attractive attire, however, all heads and eyes turned towards Papyrus when he paraded into the front entrance of Mettaton’s mansion. Mettaton’s eyes nearly bulged out of his metallic head and arousal shot down straight to his groin.

The short, black skirt fanned slightly outwards, showing off Papyrus’s long, pearly femurs. A white, frilly apron hung around his hipbone to prevent it from slipping off. The top half of the maid outfit was also black, with puffed shoulders and a low neckline that revealed his clavicle and topmost rib. Papyrus also wore dark, sheer thigh-high socks that had Mettaton wondering how it wasn’t sliding off. He stood on a pair of high heels. 

Someone in the sea of monsters and humans whistled and another cat-called. Papyrus’s pale cheeks tinged a light orange. Mettaton bristled in response and tore down the hallway towards his boyfriend. 

No one was allowed to touch his Papyrus or else they’ll suffer from his wrath.

Papyrus brightened when he saw Mettaton and attempted to dash towards him. He stumbled on his heels, cantering towards the marble floor. Mettaton caught him within his arms just in time.

“Please be careful, darling!”

“THANK YOU, METTATON!” Papyrus’s blush deepened in color.

“My, you look simply fabulous like this, Papy.”

“OF COURSE, THE GREAT PAPYRUS ALWAYS STRIVES TO LOOK THE BEST!” 

Squeaky footsteps sounded from behind Papyrus, soon revealing to be Sans in a hideously yellow, blue and red clown costume. He even had a bright red nose, a propeller cap, and red shoes that squealed every time he took a step. It was obnoxious. 

“pap really _fell_ for ya. thanks for the save, metta.” Sans winked. “he’s your responsibility for tonight so make sure you keep him safe.” 

Sans's left eye briefly flashed blue and yellow before he sauntered off. 

“WELL, METTATON, LET’S JOIN THE PARTY!”

Papyrus straightened himself to stand back up and beelined for the main room of the party. The pressure coiling within Mettaton’s core tightened as he saw a slight sway in the skeleton’s hips. He licked at his fake sharp fangs as he thought of taking Papyrus later that night.

The party went well, with Mettaton sneaking covert strokes up Papyrus’s exposed femurs, which would set his face alight in an orange glow. Fire burned within Mettaton’s soul. Instead of his entrancing others as a vampire, Papyrus seemed to have him completely bewitched. By the time two hours had gone by, Mettaton sported a raging bone. He intercepted Papyrus in a hallway and dragged his boyfriend into an empty guest bedroom. 

“I’m afraid I can’t wait any longer, darling! You have got to relieve this!” Mettaton fiddled with the buttons of his shirt and pants and flung them to the side. 

“SHALL I PROVIDE YOU WITH MY SERVICES, MASTER? WINK!” Papyrus gave a bright, playful smile, lidding his eye sockets. 

And that was the final straw for Mettaton. He caught Papyrus in a sloppy kiss, their tongues wrestling against each other. Mettaton moan deeply, heat coiling within his core. He slipped his hands under the skirt of Papyrus’s skimpy maid outfit. Unformed magic already swirled in his pelvis inlet.

“Please, Papy, my love,” Mettaton groaned. “Form those wonderful thighs of yours.”

In less than a second, translucent ecto-flesh covered Papyrus’s leg bones, stretching out his thigh-high stockings. A glistening mound materialized between his thighs. Mettaton slid a finger into the slick slit, wrenching a sharp gasp from his lover. Papyrus sank down to meet his plunging finger. He licked along Papyrus's bare clavicle. The skeleton tilted his head to the side to give Mettaton more access. He sank his vampire teeth into the ossified material, wrenching a yelp from Papyrus. He then inserted a second digit and scissored Papyrus's opening. The bony monster keened. 

“METTATON,” he panted. “I AM READY TO BE FILLED BY YOUR SILVERY ROD OF AROUSAL!”

Mettaton gave a low chuckle against Papyrus’s neck, sending vibrations against the bones there. His boyfriend arched flush against his cool, metal body. 

Papyrus’s name for his dick was so cute.

“As you wish, darling.”

Mettaton pushed his lover against the wall, gripped the ecto-flesh of his left leg to lift it into the air. Then he thrust his hard metal cock into Papyrus’s pussy. Both of them moaned simultaneously. The tight heat wrapped around Mettaton's length drove him wild. He snapped his hips back and plowed into Papyrus, who clutched at his silky cape as he met Mettaton’s sharp thrusts. Their lewd cries of pleasure bounced off the walls of the room. 

Mettaton didn’t even care if all the guests heard them. Maybe it was better this way so some of those leering human realized that Papyrus belonged to him and no one else.

Mettaton’s free hand trailed back under Papyrus’s skirt to rub circles at his clit. With two more deep thrusts, his skeleton boyfriend clenched around his member. Papyrus climaxed while screaming his name. Mettaton soon finished after.

“Oh yesss~!”

Papyrus sank bonelessly into his arms, humming contently. Mettaton pulled out and groaned when he saw his glittery pink cum leak out of Papyrus’s abused pussy, some of it dripping onto the floor. After a few minutes, Papyrus allowed his ecto-flesh and the evidence of their sex to disappear. He straightened out the wrinkles in his skirt, fixed his stockings and turned towards the door.

“THAT WAS AMAZING!” Papyrus beamed. “NOW LET’S GO BACK TO THE PARTY!”

Mettaton nodded and followed after him, only to walk out on a beach ball-sized balloon exploding in his face with a loud fart noise. Sans’s obnoxious chuckles and squeaky shoes plagued him for the rest of the night.


	8. Prostitution (Sans x various)

**Summary for the Chapter:**

> As an employee at the Pink Echo Flower, Sans not only provides services of the pleasurable kind, but he receives them as well.

**Notes for the Chapter:**

> So I swapped my original Day 8 (Roleplay starring Soriel) with Day 19 (Prostitution) because Day 8 worked better in conjuncture with Day 20 (threesome starring Sansgoriel). 
> 
> Specific pairings in this chapter are: Sans x whimsalot, Sans x pyrope, Sans x Doggo x Greater Dog
> 
>   **Additional warnings: light bondage, threesome, spitroasting, knotting, ecto-parts (undefined)**

Sans stepped through a shortcut into an inconspicuous alley in New Home and stood in front of the entrance to the Pink Echo Flower. When Sans went inside, he was met with the familiar interiors of lavender-painted walls and pink drapes hung in elaborative arches. Muffet greeted him at the reception.

“Hello, deary, you are well enough to work today?” the spider monster asked with a click of her front legs.

“yep, any takers?”

“Of course. Room two on the second floor.” She held out a pink key with the number ‘2’ stamped on it. “He seems overly stressed so try to give him a good time.”

“will do, boss.” 

Sans grabbed it as he strolled past her and ascended the stairs. It was the second door in the cyan-colored hallways. Every floor was painted a different color -- pink for the first, blue for the second, and lavender for the third. 

Sans inserted the key into the lock and turned the knob to open the door. A whimsalot from the Core sat on the queen-size bed decorated with matching blue sheets. Sans easily discerned, from the way their two-bladed wings fluttered in nervousness and agitation, that the monster was new to this type of service.

“hey there, bud, it’s ok if you’re new to this. name’s boners." His nickname for when he worked here. The pun always gave him a good chuckle. 

He offered his left hand. 

_PPPHHHHTTTTT!_

A chattering, sounding like high-pitched laughter, rang out from behind the whimsalot’s helmit.

“heheh, the old whoopee cushion trick. always a n _ice_ -breaker, eh? anyways, i won’t do anything you don’t want or agree to, capiche?” Sans reassured soothingly. 

He slowly made his way closer to the whimsalot.

“O-oh! T-thank you! I-I simply needed a break from the s-s-stress of my j-job! My boss is being entirely too unreasonable! Giving me extra shifts! I have a family too!” 

The whimsalot’s wings buzzed loudly with how fast they vibrated, and his antennae stood upright on his head.

“It’s just simply not fair!”

Sans sat down on the bed close to the monster but still giving them space to move away. He raised an arm and asked, “mind if i touch you?”

The whimsalot kept silent for a moment before he nodded hesitantly. Sans gingerly rubbed languid circles in their back. Some of the tension seeped out of the whimsalot’s body. 

“knock knock.” He tapped the wooden bed with a fist.

“Oh oh! Who’s there?” 

“boo hoo.”

“Boo hoo who?”

“aww, don’t cry. lemme give ya a good time.”

The whimsalot giggled and relaxed more. Sans asked if he could touch their wings, which they obliged after hesitating for longer than his previous question. It turned out their wings were an erogenous region. A few careful strokes later, and a burst of butterflies erupted out of whimsalot’s ghostly torso. The monster’s flying appendages oscillated in a calmer, more rhythmic manner. 

“Oh thank you Mr. Boners! I haven’t felt this good since I started my new job.”

“no problem, pal, come any time when ya need some stress relief.” Sans winked and escorted the monster back to the main floor.

His soul felt lighter every time a monster left his services looking happier than when they came in. It was worth the shame that sometimes seeped into his soul at the thought of Papyrus ever discovering this secret job of his.

\---

Sans moaned as pyrope’s sinuous, flaming body coiled tightly up his spine, around his arms and through the spaces between his ribs. The heat, filled with eager, dominant and caring intent, literally twisted through him. The room filled with soft rattling. Sans floundered uselessly in the fiery bonds as the top of pyrope’s body and his head crept towards Sans’s bare pelvis. 

Pyrope paused and asked, “I continue?”

Sans nodded his head vigorously; he was about ready to explode from the pent-up pleasure.

With the lick of embers at his sacrum and coccyx, he came with a throaty cry. Pyrope immediately released his hold on Sans and slid off of the skeleton’s body. He bounced up and down like a spring, waiting for Sans to come back down from his euphoric high.

“Thankssss for indulging my fantassssiesss,” Pyrope hissed. His head shifted to inspect for any burn marks. There was a faint one located on Sans’s lower spine. “I’m ssssorry about that.” He indicated at the dark splotch on the normally white vertebrae.

“eh, i’m fine. make no bones ‘bout it," Sans waved off, suppressing a wince. He didn’t hold it against the monster.

Pyrope left looking unsure but with a brighter color to his flames and a springier bounce in his steps. When Sans shuffled haltingly down to the first floor, Muffet was waiting for him with a jar of salves to treat burns. 

“Make sure you use this before you leave, deary,” she insisted.

“thanks.”

Another day, another monster serviced to contentment. The burn mark was gone by the time Sans got back home to Snowdin.

\---

One day, Sans went to work feeling more down than usual. Papyrus kept pestering him about his “other job”. His brother didn’t know what he did, but the younger sibling had figured out that Sans’s worked more hours than normal. Sans had always been careful at picking shifts after Papyrus’s bedtime story, when his brother was asleep, but he’d slipped in the last few days. 

If Papyrus ever found out that he worked as a prostitute at a brothel, what would his brother think?

Doggo and Greater Dog, his clients for the day, noticed his despondent mood the moment he’d stepped into the room. His shoulders were slouched heavily and dark circles lined the bottom of his sockets. 

“You need to RELAX, Sans,” Doggo advised. He was the only one that still called Sans by his actual name instead of his stage name here. But he also knew how to keep a secret when asked.

He brushed his paws along Sans’s shoulders, massaging the rigid magic collecting there. Sans sighed and hummed in response, closing his eye sockets. Just for once, he wished he could lay back and do nothing. 

“What’s bothering you mate?” 

Greater Dog barked and nodded in agreement to the question.

“just my mind goin’ against me again,” Sans answered with a shrug. “nothin you two should be worrying ‘bout. besides, didn’t you two request me? should probably start doin’ something, heh.”

Sans made to get up, but was caught by surprise when Greater Dog suddenly scooped him up into his arms. Greater’s fur rubbed along his bones like silk, wracking his frame with shivers. He was turned around to face Doggo, who had apparently removed all his clothing. 

“Perhaps it’s time we did something for you, as a show of our appreciation.” Doggo leaned into Sans, their faces inches apart. “May I?”

Sans eyes widened, and he nodded with consent. Doggo pressed his snout against Sans’s teeth, and licked it with his tongue. Sans granted it entrance into his mouth and summoned his own. The dagger-thrower explored the inside of his mouth, tracing over his blunt teeth and slightly sharp canines. Meanwhile, Greater was trailing his tongue along Sans’s cervical vertebrae and swept his large paws up and down Sans’s legs. A muffled moan escaped Sans’s mouth as his magic flared in arousal.

Doggo broke away from the kiss, a trail of saliva breaking off as they separated. Blue dusted Sans’s cheeks, and his ribcage expanded and fell rapidly. Sans gazed at Doggo through lidded sockets.

“That’s a good look on you, Boners,” the sentry dog chuckled in good jest. “Look at what it’s doing to me.”

Doggo pumped his massive erection. Greater panted above him, his large claws fumbling towards his pelvis.

“Can we take you from both ends?” Doggo asked eagerly.

Sans nodded at the thought of their massive cocks filling him, taking him, and allowed the magic at his pelvic inlet to form an opening. Greater spent ample time preparing him and slicking the entrance, using his tongue to plunge in and out. Doggo had caught him back into a sloppy kiss. Drool leaked from the corners of his mouth.

After Sans was covered in slobber, Greater carefully set him on all fours on one end of the plush bed. His head faced the head of the bed and was aligned with Doggo’s thick, throbbing member. He ran his blue appendage up and down the length, lubricating it with his saliva. Doggo howled and rapidly stamped his hind legs.

The bed suddenly sank down as Greater climbed onto the bed behind Sans. A head prodded against his opening, and Sans whimpered. Slowly, Greater pushed it inside. Sans panted and keened at the stretch. The white dog stopped to give him time to adjust. He waited for Sans’s nod to continue until his length disappeared within Sans. Sans had never felt so full. 

“Ready for another? Blink three times if you want us to stop.”

“ok. heh, fill me up,” Sans quipped.

He opened his mouth as wide as it would go and worked his way taking in Doggo’s whole dick. Having been prepared from earlier, it slid down his conjured throat with relative ease. Both sentry dogs stilled briefly before they began to move. Greater held onto Sans’s hips as he rutted with increasing ferocity. His moans were choked off by Doggo’s member plowing in and out of his mouth. 

At a certain point, Sans’s mind became a haze of never-ending pleasure. It was a space he rarely entered despite his job description. Both canines thrusted as deep as they could go and halted abruptly. Sans felt both cocks swell.

Oh shit.

Doggo and Greater Dog blew their load, filling Sans with their cum. They couldn’t even pull out until every drop was pumped into him. 

Then he blacked out.

When Sans came to, he was lying in a soft, clean bed with sheets smelling of freshly baked cookies. Sans groaned as he attempted to get up. Two pairs of soft paws came to support him. He blinked and saw Doggo and Greater Dog each sitting on a side of the bed.

“You alright, mate?” Doggo asked, voice dripping with concern and guilt. 

He, surprisingly, felt fine. Great even (and clean!). Muffet must’ve given him something while he was out?

“The spider lady almost killed us when she came up.”

Yep, sounded like something she would do.

“hey, you’re alive.”

“After explaining multiple times that it was all consensual. The lady scared us good. Anyways, we didn’t mean to be so rough. Sorry.” Doggo’s ears drooped.

“hey, hey, you can’t be sad when ya leave here,” Sans said. He petted both dogs, and they instantly perked back up. “‘sides, i gotta thank you two for a good time. lookin’ forward to next time.” 

Both Snowdin residents agreed excited and bid their good-byes. Sans chuckled as they left.

Working at the Pink Echo Flower, Sans wasn’t the only provider. The customers always repaid in kind, and for that, Sans was thankful. Maybe one day, he would reveal this secret job to his brother.

**Notes for the Chapter:**

> This is another one-shot that may potentially become a short, multi-chaptered fic. I even had to remove the Sans x Shyren scene due to length.


	9. Lingerie and Frottage (Asgoriel)

**Summary for the Chapter:**

> It's a special occasion and Toriel brings out her Sexy Times outfit.

**Notes for the Chapter:**

> **Additional warnings: blindfolds, nipple play**

Asgore wrung his large hands nervously on the edge of the double-king sized bed. His vision was completely obscured by a thick, black blindfold. Soft, padded footsteps approached him, and his ears perked up in response. 

He had come home after a day of ambassador work to find Toriel making an elaborate dinner of snail casserole, sauteed vegetables, a class of red wine and her famous butterscotch pie. It was absolutely delicious, and when he asked for the occasion, she responded with a coy smile. 

"It's the one-year anniversary since we started dating again."

The answer had his soul fluttering in his chest during the whole dinner.

Asgore jolted when Toriel’s silky fur rubbed along his bare legs. She caught his thick arms and led it to trail down her body. The pads of his paw brushed against lace and fur. He felt her thighs lift up to drape over his own. After a few pause, she rutted her crotch against his legs. It had a glossy, fabric texture to it. 

Moments later, the fabric wrapped around Asgore’s head came off to reveal Toriel’s scantily clad form. A transparent, black mesh-stripe lingerie dress draped over her torso, reaching only down to her upper thighs. She was bra-less, though her ample breasts were partially covered by elegant spiral designs made from lace. Toriel turned around to display her bodacious butt; it was barely covered by the matching-colored thong. Her eyes were lidded with a sultry look that sent heat right down to his dick.

“T-Tori! You look…” Asgore stuttered.

“Hmm? What about how I look, Gorey?” There was a deep, husky quality to her voice that made his underpants uncomfortably tight.

“Ab-absolutely stunning!”

Toriel giggled. She then straddled on top of him and ground against his upper thigh, ripping a growl from Asgore. His paw shot to her right breast and gave it a squeeze. Toriel gasped and panted in response. Through the silk lace, he twirled and pinched her nipple between his thumb and forefinger, forcing a moan to escape from her maw. Meanwhile, she continued to thrust rhythmically against his erection through her black panties. Asgore met her movements. Growls and moans soon filled the room.

Just as the pressure coiling within Asgore was about to snap, he paused to lift up Toriel’s lingerie dress. With a quick glance at his former wife (and current girlfriend), he brought his face towards her left breast, the right one still currently occupied by his hand. 

“Will you allow me to pleasure you first, Tori?” Asgore cringed inwardly at the hesitancy in his voice. He simply wanted this reconnection he had with Toriel to work out.

“Yes! Please!”

Asgore licked at Toriel's left nipple, making her keen sharply while his other hand continued to fondle her other boob. They resumed their dry humping. Asgore bit lightly at the erect nub and furiously kneaded the other one. Before long, Toriel threw her head back, eyes closing tightly, and screamed out his name in ecstasy. He felt a damp spot on his legs where she had just been rubbing. The sight of seeing her in such bliss sent Asgore over the edge.

“Toriel! I still love you!” he confessed.

Dread immediately yanked him out of his frenzy at his mistake. He hid his face in his hand in embarrassment. To his surprise, however, a pair of paws gently grasped his own.

“You know, Asgore, it’s been almost 10 years since we’ve reached the surface, and I’ve long forgiven you for your past choices.” Toriel’s lips lifted to a tender smile. “I love you too.”

They nose nuzzled for the first time in over 10 years.


	10. Fucking Machine (Sanster)

**Summary for the Chapter:**

> Gaster needs a way to extract soul fluid from Sans. What better way than through a pleasurable device of his own invention.

**Notes for the Chapter:**

> Anyway, in case my description was not clear enough, [here’s a MSPaint drawing of the Extraction and Pleasuring Machine™ ](http://knowmeknot101.tumblr.com/post/166281064112/soul-device-from-a-coct-full-of-kinks-day-10).
> 
>  
> 
> **Additional warnings: soul sex, souls as genitalia, sensitive bones, multiple orgasms**

“you sure this is gonna work, doc?” Sans asked with uncertainty. 

He currently sat naked on a strange apparatus that his eccentric boss had created. Gaster needed to collect fifty milliliters of soul fluid to examine the components that made up Sans’s soul. Rather than have him endure the excruciating pain that came with Soul Extractions, Gaster suggested a more… pleasurable experience for Sans. He’d spent days toiling over the device, using multiple resources from human books on “porn and sex machines” to come up with this invention.

The narrow cushioned seat, located two feet from the ground and held up by a triangular stand, allowed just enough space for Sans to sit his ischium and sacrum against it but nothing more. His legs were also forced apart by a V shaped leg rest and strapped down by thick, leather bands to keep him from falling off the machine. The same straps tethered Sans’s spine to a thick, metal T-shaped pole rising from behind Sans’s seat. Each of his wrists was bound to one side of the horizontal part. Two retractable arms, with Gaster’s detachable hands, dangled from the ends of the T.

The last section of the machine was the soul extraction device. Due to how Sans was positioned, with most of his pelvis off the seat and on full display, a five centimeter diameter tube had been inserted into the hollow center of his pelvis. Despite the initial discomfort, the longer the tube stayed within him, the more it excited the magic swirling around in that area. The tube was connected to a vacuum device that fed it to a one-hundred milliliter flask. 

Gaster stood at the side. His two other unoccupied hands signed, **‘Are you ready, Sans? If it ever gets too much, just tell me to stop.’**

The hesitancy in Gaster’s voice surprised Sans, given how excitable the Royal Scientist usually got when the two of them tried new experiments.

“don’t worry, dings, i’m in good _hands_.” Sans waggled his bone brows and pointed his phalanges at the ones hovering motionlessly on either side of him.

Gaster huffed. **’Fair enough. Here we go.’**

The scientist’s eyes flared purple. The cool thing about this apparatus was its activation by Gaster’s magic instead of electricity or power; it meant that Gaster had all the control. 

Sans startled when feather-light touches dance down his ribcage and then broke away. They continued this style of teasing, shifting from his outer ribs, across his sternum and in between the disks of his individual vertebra. Every time Gaster’s palms paused, Sans attempted to arch his spine for more contact, though it was fruitless given his bindings. When Gaster finally stopped his teasing, Sans’s soul swelled and pulsed cyan. Droplets of soul fluid trickled down into the tube resting within his pelvic arch. 

“ah, doc… please st-stop teasin’,” Sans begged. Sweat trickled down his skull. 

Gaster smirked widely and gestured, **’Oh, but I’m having so much fun playing with you, my lovely assistant.’**

“can ya just get to the point!”

 **‘So much for Patience.'** Sans could practically _hear_ the sarcasm despite not hearing a word from Gaster. Sans grunted and whined from the lack of stimulation. 

Eventually, Gaster conceded. **'As you wish. I always treat my favorites well.**

Not a second later, the hands attached to the device slipped inside Sans’s ribcage to caress the slick humps of his soul. Sans moaned loudly, and rattles filled the room as he squirmed in his bonds. Gaster continued to tease the inverted heart, bringing it lower and lower down Sans’s small frame until the bottom half inserted itself snugly into the extraction tube. The tip was still exposed and dripping.

**‘Now the fun begins,’** Gaster's smirk widened to the point of nearly splitting his face. 

His sockets flashed violet again. A suctioning noise suddenly erupted from the extraction device.

Sans screamed as the tugging sensation at the culmination of his entire being led to his first orgasm. The liquid excreted from his soul was immediately vacuumed through the Extractor and into the collecting flask. 

But Gaster’s hands didn’t stop there. Without even pausing for a break, they continued to assault Sans’s bones, fondling his ilium, sacrum, and pumping his lower spine. A rebound of pressure coiled within his soul. A digit dug into top-most sacral foramen and within less than a minute, Sans was coming again. He squeezed his sockets shut, tears beading at the corners from the overstimulation, and panted raggedly. 

After the second orgasm, Gaster had decided to give Sans a respite. When the ministrations halted, Sans snapped his eyes open to stare at the collecting jar. It only filled to the 23 milliliter mark. 

He had to come at least two more times.

When the Royal Scientist resumed, he increased the suctioning, and had his phalanges rub and twirl the pointed tip of Sans’s soul. Liquid glistened at the tip. After a particularly hard pinch, another gush of blue fluid expelled from the organ like a compressed water balloon. By this time, Sans’s voice had become hoarse from his cries of pleasure, and drool leaked out of his mouth. He quivered with his restraints, the only things keeping from slipping onto the ground. 

After climaxing two more times, Gaster finally stopped the machine. The collecting flask contained 54 milliliters of Sans’s soul fluid. The Royal Scientist carefully loosened the bindings, and caught Sans before he hit the floor, holding him bridal style. Sans leered up at his boss through lidded sockets.

“geez, dings, that was a _suckingly_ great experience, heh,” he mumbled. He sounded ready to take a nap. 

“That was a real stretch of a pun, Sans. I expect better for next time,” Gaster comment finally with his voice.

“whoa, there’s a next time? can’t wait. though maybe you can give it a try, doc.”

“We’ll see.”


	11. Gags and Orgasm Denial (SpicyHoney)

**Summary for the Chapter:**

> Edge goes into heat. Thankfully his boneheaded husband is there to help.

**Notes for the Chapter:**

> \--- denotes change in POV
> 
> **Additional warnings: Ecto-vagina, ecto-penis, soul fondling (noticing a theme here, haha), vaginal fingering, penetrative sex**

Edge was acting strange. He had apparently left for work without even making breakfast, since the leftovers that would usually be left on the kitchen table for Stretch, was absent. Instead, a note had been left for him in the spot where his eggs should’ve been.

_I AM BUSY THIS MORNING. PREPARE YOUR OWN BREAKFAST._

Although his husband had always been short-tempered and curt, this was more so than usual. The slight shakiness in the written text was also suspect. He decided to call Edge later on during the day to check up on him. Luckily, Stretch worked from home at an easygoing IT job. Who knew he had such a knack for computers after his universe had finally reached the surface.

At lunch time, Stretch called Edge’s cell. It rang three times before the other picked up.

“WHAT THE HELL DO YOU WANT?!” Despite the irritation prickling his voice, it carried a breathy quality. 

“you left so early... without even makin’ me breakfast—”

“I-I DID IT ON PURPOSE TO TEACH YOU TO MAKE FOOD Y-YOURSELF!” Edge snarled defensively.

“hey, hey, calm down. you alright there, bud?”

“STOP—AH~!” 

Was that… a moan? 

“JUST LEAVE ME ALONE!”

There was a click, and the call ended. Stretch stared at the phone, puzzled. That definitely sounded like a moan. Then he remembered how Edge had been ranting the other day about feeling “UNDER THE WEATHER” and excruciatingly warm.

Just like that, understanding dawned upon Stretch. His teeth lifted to a smirk. He turned towards the clock on the microwave and saw that it was 12:30 PM.

He still had hours to prepare.

\---

Edge suppressed the needy groan that threatened to break free from the confines of his jaws as he paced around at the police station where he worked. He had woken up this morning feeling needlessly warm with his bones tinged the red of his magic. Every movement brought about a tense coil within pelvis and soul. He had quickly gotten changed and fled the house, not wanting Stretch to see him in such a manner.

Of course, he recognized what this was — his heat. 

The last time he experienced it, he’d just turned sixteen, and it’d left him practically incapacitated. The most embarrassing aspect of it was how compliant and _weak_ it made him. The other problem was how long it lasted. 

There was no way, even if he threw away his pride to ask Stretch for help, that Stretch would have the stamina to last the duration of his heat. 

Ever since he’d gotten off the phone with Stretch, his newly-wedded husband plagued his mind. Every time he pictured the orange-clad skeleton, the coiling pressure would tighten and speed up the pounding of his soul. Edge had gone to the bathroom four times that day to relieve some of the growing heat. And when every trip left him unfulfilled, Edge’s resistance to asking for help dwindled, though his stubbornness still won out. 

His trips didn’t go unnoticed by his colleagues, as they gave him inquiring stares by the fifth time. They also noticed his scent; they seemed to think it was a new cologne he’d begun using. 

“Yo, Edge, is something wrong? You look kinda flushed. Are ya coming down with something?” a co-worker asked. 

A rebuttal sprang onto the tip of his tongue; but Edge decided he had had enough. “I DO FEEL ILL. I AM TAKING THE REST OF MY SHIFT OFF.”

He didn’t even wait for the co-worker’s response. He turned and stormed out. The cool outside air did nothing to the heat burning within him. He tight, leather pants definitely didn’t help matters, his summoned pussy brushing against it with every step he took.

Finally, after speeding back home, he slammed the door open to their finished basement. They used it as a makeshift bedroom; it was furnished with a queen-size bed, a bathroom, and had a couch and TV. Whenever his and his brother’s doppelgangers from other universes visited, this would be used as the guest bedroom.

He locked himself into the basement, hoping Stretch wouldn’t suspect his problem. It wasn’t as if he hadn’t already suffered through it alone before.

Edge stripped away his sweaty clothes in an uncharacteristically haphazard fashion, setting it aside in a pile by the foot of the bed. Then he laid, splayed out, on top of the cream-colored sheets, exposing his summoned mound. His soul glowed and leaked with liquid magic. He gingerly brushed a phalanx against the plump, glowing lips, his breath hitching, and pushed the finger inside. He gave a stifled moan. Realizing that his cries may eventually become loud enough for Stretch to hear, Edge reached over to grab his trademark crimson scarf, forced it through his mouth and tied it tightly around his skull.

He plunged his pointer in and out of his tight hole, trying to reach as deep as he could, while his thumb pressed at his clit. No matter how rough he fingered himself, Edge couldn’t seem to reach a peak, the pressure coiling within his pelvis only growing tighter and tighter.

Suddenly, in his haze of pleasure and frustration, he heard a faint crack. Through lidded sockets, he saw Stretch standing by the foot of the bed with a wide smirk etched on his features. He wore only his orange hoodie.

He frowned in mock pain, “i’m so hurt, edge, that you would not invite me.”

Forgetting that he had gagged himself in midst of his heat, his rebutted was muffled.

Edge made to remove the scarf wrapped around his mouth, but before he could, Stretch appeared in top of him in a blink of an eye and pinned his wrists down onto the bed. A muffled cry escaped him when Stretch’s bare femur rubbed along his dripping slit.

“you could’ve asked me, bud, since we’re married now. let me help?”

Stretch’s predatory expression positively set Edge’s bones alight, and primal desire burned within his core. He finally relented and consented.

Stretch shifted Edge’s arms up to trap his pinned wrists in one hand above his skull. With his free hand, he reached down to tease at Edge’s pussy, sliding his phalanges along the folds. After two more strokes, Stretch slipped two fingers inside and began to pump them in and out of the opening. Edge gave a muted keen and met his husband’s plunging fingers.

Pleasure exploded within him when Stretch hit his G-spot repeatedly and roughly circled his clit. His sockets closed as his spine arched off the bed. Just before he climaxed, however, Stretch withdrew his hand, wrenching a pitiful whine from Edge. He replaced it with the lead of his erect cock. Stretch panted above him, skull flushed with arousal. 

“if you want me to last long, you gotta trust me,” Stretch murmured. He removed Edge’s gag.

“THEN FUCK ME ALREADY, YOU LAZYBONES!”

“heh, nice one.” Edge barely recognized the unintentional pun. “here i go.”

Without warning, Stretch sank his dick to the hilt and gently cupped Edge’s soul within the hand that had been pleasuring Edge; it was still slick with his pussy juice. 

“HNNNG… AH~!”

And then he felt it — Stretch’s intent on denying him release.

“the harder you come, the shorter your heat will last.”

But Edge didn’t care; he rutted futilely against his significant other. Stretch finally started thrusting, going at a slow and steady pace. It constantly drove Edge to the brink of orgasm but never enough to make him come. The wet fingers wrapped around his soul made sure of it.

Eventually, the pressure mounting pressure became unbearable, and tears sprung to his sockets. He barely registered the pleads pouring out of his mouth. 

“stars, you’re gorgeous like this, edge,” Stretch groaned at Edge’s sweat, tears and drool-covered face. 

“PL-PLEASE!”

Stretch grinned, his expression smug. 

“wowie... never heard you beg before. i like it.” He paused mid-thrust. “do it again.”

Edge’s face turned red as a tomato. He turned his head to the side and stammered, “PL-PLEASE, Y-YOU B-B-BONEHEAD, PLEASE LET ME C-COME!”

Stretch nearly came right then at Edge’s shaky tone and display of submission. He picked up his pace, finally releasing Edge’s wrists and soul to grip his hips. Several deep thrusts later, Edge felt himself bursting at the seams. He came so hard, his vision blacked out momentarily. Seconds later, Stretch followed, filling his ecto-vagina with more cum. 

Although the heat abated somewhat, he knew it would only take a few minutes for it to rear back at full power. The two of them remained connected, and Stretch clacked their teeth together. Edge forced the most unpleasant scowl he could. 

“YOU’RE SUCH SAP!” his ruby eye lights darted to the side. “BUT I LOVE YOU FOR IT, YOU BONEHEAD!”

A beaming smile stretched on his husband’s skull. They kissed again and continued until the next morning.


	12. Tentacles (Flowey x Papyrus)

**Summary for the Chapter:**

> Flowey gets a strange and surprising request from his friend Papyrus during one of his many runs.

**Notes for the Chapter:**

> **Additional warnings: vine bondage, ecto-penis, oral sex, penetration, vaguely implied fontcest**

Flowey had many interesting runs through his various RESETS (he dubbed them “Playthroughs”). But never did he receive such an odd request from one of his favorite “toys”.

Papyrus.

He was truly a fun monster. He was easy to manipulate and absolutely hilarious to hang around with, listening to all his rants about how great he is or how he’ll become part of the Royal Guards. And best of all, he was not boring. Not completely, at least. More accurately, boredom didn't come as readily when he hung around with Papyrus. For the longest time, Papyrus literally kept Flowey going; the skeleton gave him the reason to try every possible choice.

But this? This definitely took the cake.

“You want me to do WHAT?” Flowey blinked, his black eyes budging. 

A soft orange glow flitted across Papyrus’s cheeks, and the lanky skeleton twisted his gloved hands together. 

“I WATCHED A MOVIE RECENTLY… ABOUT OCTOPUSES AND… TENTACLES.” Papyrus’s sockets darted to the side, his lack of his usual loudness catching Flowey off-guarded. “AND I WANTED TO SEE WHAT TH-THEY ARE LIKE… RUNNING THROUGH M-MY BONES. I’VE TRIED ASKING MY BROTHER BUT HIS ENTIRE FACE WOULD TURN BLUE, AND HE WOULD DISAPPEAR WITHOUT GIVING ME AN ANSWER.”

So apparently Papyrus wanted to be treated like a female lead in one of those garbage anime Alphys always watched...

A wide sneer appeared on Flowey’s face. 

“Alright~, since you’re such a good friend of mine, Papyrus, I’ll do it.”

"REALLY?"

As a response, three smooth, green vines sprang out of the ground and wound around Papyrus faster than he could blink. Two coiled around his femurs, spread them apart and yanked them down so he was kneeling on the snow-covered earth. The third one looped Papyrus’s arms together behind his back and forced them towards the ground in a way that arched his spine, exposing his ribs into the air. 

“FL-FLOWEY!” Papyrus gasped at his strained position.

Flowey loomed over his bone friend’s skull with a hungry expression. A fourth vine snuck under Papyrus’s armor and twisted up his spine until it reached into the inside of his ribcage. Yellow flowers sprouted from the vine to brush against the underside of each rib. Papyrus shuddered violently in his bonds. Flowey could feel the pent up, aroused magic circling within Papyrus's bones.

Something unexpected flickered to life within Flowey’s core.

“Golly, Papyrus, I never pegged you as such a dirty monster. You like this don’t you? Is this your. Dark. Secret. Fantasy?” With each punctuated word, his vines constricted tighter and tighter. 

He was rewarded with a lewd moan from the skeleton. 

“Would you like me to go further?”

Papyrus snapped his sockets shut and opened his mouth in a silent scream. Flowey waited, sliding his roots back and forth throughout Papyrus.

“PL-PLEASE CONTINUE, FL-FLOWEY!”

Flowey nodded with enthusiasm and darted towards Papyrus’s pelvis. With a swish, Flowey removed Papyrus’s shorts and black tights.

“Can you make something or should I just rub off your bones?”

With a grunt, the orange magic swirling within Papyrus’s pelvis morphed into a puckered entrance and a long shaft. Lust burst within Flowey at the size of Papyrus’s cock. He curled his main stem around it and pulled it close to his mouth.

“FL-FLOWEY?” Papyrus struggled to lift himself but the vines held fast.

“Don’t worry, Papyrus, I’ll make you feel so good, you won’t even remember this! Ahahaha!”

Flowey nibbled at the large head while he allowed another, thicker vine to creep towards Papyrus’s back entrance. It teased the opening, releasing oily sap to loosen the tight muscle. Meanwhile, Flowey worked his mouth down Papyrus’s shaft, coating it in his plant fluid. His jaws became sore from the strain, but he kept going. Papyrus quivered and panted, mewls of pleasant escaping his jaws.

Realizing he should quicken his pace in case that smiley trashbag interrupted their _friendship bonding_ , Flowey forced the thick vine into Papyrus’s hole and bobbed his head up and down the other’s members. His teeth scraped against the slit at the top. The flowers within Papyrus’s ribs began to shift as well, creating a maelstrom of white-hot pleasure. 

Papyrus suddenly tensed, and Flowey felt Papyrus’s cock swell. The tall monster cried out his name, and moments later, warm, magical release squirted into Flowey’s mouth. The vines retreated from the skeleton’s body, who collapsed limply into the snow.

“Well that was fun,” Flowey huffed slightly. “It’ll be fun to do that again.”

And he did. Over and over again until he eventually got bored. Like always.


	13. Medical Play (US Undyne x UT Alphys)

**Summary for the Chapter:**

> Alphys appears in the Underswap universe and receives a pelvic exam from that world's Undyne.

**Notes for the Chapter:**

> **Additional warnings: vaginal insertion, vaginal fingering**

Alphys blinked awake and instantly closed it due to a blinding light shining down at her face. She turned her face ninety-degrees to find herself on a cushioned examination table. With her soul pounding, she sprang up from her prone position, thankful that she hadn’t been strapped down. Peering around, she realized she was in a lab not to dissimilar to her own. Even the computer console had tons of food crumbs over it.

Alphys couldn’t remember how she’d gotten here, only that she and Sans had been messing with a machine that led to alternative timelines and universes. The image of a bright white flash filled her mind. Just when her memory came back to her, the door to the room swung opened.

Undyne stood in the doorway. 

Except she wore a long white lab coat and had her hair tied up in a messy bun. Her one eye darted around, and she gasped when her eye caught sight of Alphys. Alphys’s soul fluttered within her chest at the sight of her secret crush dressed so similarly to herself.

“Al-Alphys!” Undyne stuttered.

But wait… Undyne never stuttered. At least, not ever since Alphys had met her. And since when did Undyne work in a lab? She hated science. Was she really in her home universe?

“H-hi, Undyne. I’m Alphys, b-but probably not the one you k-know.” 

Recognition dawned on this other Undyne’s face, and she nodded. “Are you from another universe? Papyrus’s mentioned the Multiverse Theory to me a few times.”

“Yeah. I was working, um, w-with Sans in my home world.”

The two of them fell silent. Alphys fidgeted with her hands.

“D-d-do you m-mind if, um, I e-examine you?” this world’s Undyne, who Alphys decided to nickname “Selkie”. "To check for, uh, d-differences, y-you k-know. B-but it's t-totally ok if you d-don't want to.

“O-oh, uh, s-sure.”

Alphys allowed Selkie to lead her back to the examination table. She slowly shed her lab coat, noticing that Selkie went to the cabinets to retrieve some medical equipment. She was easily able to reach the top shelf, which Alphys always had issues reaching. Then again, Undyne was almost a head taller than her.

Selkie eventually came back with a thin stainless steel rod that was concave slightly at the end, a wand with long bristles, and a metal instrument resembling a duckbill. The top and bottom pieces were about an inch apart. Although Alphys was a doctor, she specialized in soul transplantation and monster biology; human biology, she only knew from her anime and some medical textbooks that landed at the dump. She only recognized the device as a speculum and knew of its use due to reading about it in one of the books labeled “Women’s Health.”

Arousal shot down to her crotch. The Undyne turned to face her. As soon as she did, her lips curled into a wide smile, appearing almost like Undyne’s passionate ones. 

“Nice shirt.”

It was a black t-shirt, with periodic element Um with the caption “The Element of Confusion”, she always wore under her white coat. Alphys giggled in response. She found herself feeling more and more comfortable around this alternative Undyne. Maybe her love transcended dimensions.

“Uh, it would be easier if you… t-took off your p-p-pants.”

Heat rushed into Alphys’s face.

“I- I m-mean… O-only if you w-want.” Selkie’s fiddled with her sleeves.

“I’ll d-do it.”

Alphys slipped off her sweatpants and laid back down on the examination table. Undyne rolled over a small metal cart loaded with the equipment she had picked. 

Alphys spread her legs. Her breath hitched when a latex-gloved hand brushed along her folds and stuck two fingers into her vagina. The two fingers prodded at her opening, feeling around for any irregularities. 

With Selkie’s two fingers still fingering her opening, the fish monster’s other hand gently settled on top of Alphys’s stomach. She gave a firm push on the abdomen, wringing a lewd cry from Alphys. Her pussy became slick with her arousal at the sensations and the fact that Undyne, or a version of her -- she was still Undyne in Alphys’s eyes --, was performing a pelvic exam on her.

When Undyne removed her hands, Alphys whined from the loss. Undyne grabbed the speculum and grinned widely.

“Do you know what this is for?” The sudden confidence in Selkie’s voice caught Alphys by surprise. She nodded. “Good. Let me know if it gets too uncomfortable.”

Undyne lined the two prongs of the speculum against the cavity and slowly pushed inwards. When the instrument was initially forced in, it drew tears into Alphys’s eyes. A tight pressure filled her entire being -- one that required release. With a wet squelch, Alphys felt the pronged part of the device insert completely into her vagina. She panted and moaned at the stretch, edging just on the cusp of discomfort. 

Undyne’s face loomed over her one, her blue cheeks tinged red. 

“Just a b-bit more.”

Undyne picked the steel rod and dug the concave portion into the back of Alphys’s pussy. Stars flashed in her vision, as wherever the other was hitting, it sent pleasure throughout Alphys. Undyne plunged it in and out of her channel, scraping it against her back walls. They clenched tightly against the rod. Alphys threw her head back and arched her back off the examination table. 

Springy bristles brushed against her clit, circling the engorged nub. Alphys came with a screech. It didn’t stop there; the rod was removed, and the brush swept through her pussy, hitting her cervix. She keened and quivered like a leaf from the overstimulation. 

Undyne brought up the wand covered in Alphys’s juices and placed it into a glass jar. Then she pulled out the speculum, causing the leftover magical release to drip onto the linoleum floor. Alphys sighed in a content haze and felt Undyne cover her legs. She eventually fell asleep.

When she woke up, Sans greeted her, expression relieved. 

Had that all been a strange dream?

But when Alphys reached into the pocket of her lab coat, she saw a note written in Undyne’s familiar handwriting.

_Come visit again._


	14. Sensory Deprivation and Incest (Swapcest)

**Summary for the Chapter:**

> US Sans and US Papyrus's first time.

**Notes for the Chapter:**

> \--- denotes change in POV
> 
> **Additional warnings: frottage, blindfolds, ecto-penis**

Sans couldn’t remember when exactly his feelings towards Papyrus became more than platonic. When the two of them worked together to create his sky blue battle body? When Papyrus always praised how magnificent he was? 

Or maybe the fact that, despite being three years older, Papyrus always acted as the elder? He was the one that worked several jobs to pay for the bills and maintained their stable living situation. After all, Papyrus oftentimes got mistaken for the older brother. There were times Sans wished he could give back more to Papyrus. 

Papyrus was his world. And it wasn’t as though Papyrus didn’t feel the same way. Sans had caught Papyrus jerking off numerous times in his room, hearing muffled cries of his name. Why had his brother never told him this, Sans didn’t know.

At some point, he decided to confess. The best time would be after Papyrus finished reading him his bedtime story. Sans, in all his expertise at understanding his brother, knew he couldn’t be too straightforward in his confession lest he scare Papyrus away. 

During that evening, he let his gloved hands linger longer than usual against Papyrus’s arms. He also leaned closer, pressing their bodies together. The dusting of orange on his brother’s face didn’t go unnoticed by Sans. He took it as a good sign when Papyrus didn’t flinch away, but returned the gesture.

By the time “Fluffy Bunny” was over, the two of them were so close to each other that Sans could sense the heated magic coursing throughout Papyrus. Then, without warning, Papyrus ground his pelvis against his, sending sparks of pleasure within Sans.

“PAPY!” He responded by rutting back.

“hey, kiddo, lemme show ya somethin.”

Papyrus’s left eye flared yellow-orange. This time, when he rubbed against Sans, Sans felt a long, hard bulge under his sibling’s sweatpants. Sans’s star-shaped eye lights expanded in wonder as he fondled the organ. Papyruss erotic groans had sent magic to pool at his own pelvis.

“WOWZERS! IS THIS WHAT THOSE HUMAN MALES CALL A PENIS, OR COCK?!”

A choking sound came from Papyrus’s throat, and his sockets widened.

Sans sighed and folded his arms in front of his chest. “I AM NOT AS NAIVE AS YOU THINK, BROTHER. BESIDES, ALPHYS HAD MENTIONED IT A FEW TIMES WHEN GUSHING ABOUT HER ANIME.” Sans stood up on the bed with his arms akimbo. “TEACH ME HOW TO MAKE ONE TOO, PAPY!”

After the initial shock from Sans’s revelation faded, Papyrus conceded, “heh, alright kiddo, but we gotta go slow so your magic doesn’t end up stuck.”

Papyrus shuffled out of his sweats to reveal a shaft that illuminated the dark room orange. What it lacked in girth it definitely made up in length. Sans gaped at it for several seconds before a chuckle snapped him out of his daze. Although a wide smile graced Papyrus’s teeth, his cheekbones were flushed orange, and there was an air of hesitancy about him.

With his soul churning relentlessly with arousal, Sans also stripped away his clothes. His cyan magic swirled as an amorphous blob around his pelvis. Papyrus offered his open arms in the semblance of an embrace.

“it’ll be easier if you sit with me.”

“SO YOU CAN REMAIN IN THE SAME SPOT?” Sans rolled his pinpricks of light. “AS EXPECTED OF SUCH A LAZYBONES.”

“heh, what can i say?”

Sans settled into Papyrus’s lap, the taller skeleton’s cock pressing against his back sacrum. He shivered. Papyrus trailed his left hand up and down Sans’s ribs while his right shaped the magic in his pelvic arch. Sans ground his pelvis against his brother’s cock. Sans squealed when something wet and squishy licked at his clavicle. 

“P-PAPY!” Heat rushed into his cheeks.

“is this ok, bro?”

Sans gasped and nodded, tilting his skull to give Papyrus better access.

A moan fled out of Sans’s mouth as his brother’s expert tongue dragged along his neck bones. All of his brother’s touches became too much. With a bright flash, his magic shifted into a thick member four inches in length. Sans was disappointed that it wasn’t as impressive as his brother’s, but he didn’t let it show.

“ARE YOU IMPRESSED BY ITS MAGNIFICENCE, PAPY?” Sans puffed out his chest.

“it’s beautiful, kiddo.” 

Papyrus gave a lazy grin that increased the pounding within Sans’s ribcage. His brother’s large palms engulfed the blue cock and gave it a single pump while his thumb fingered the slit at the top. Sans keened and thrusted into the younger’s hand. The mounting pleasure was becoming too much. Sans knew if Papyrus kept going, he was going to orgasm. 

He couldn’t allow that to happen so quickly. Besides, his brother was so cool to show him this. Why should he not return the favor?

“ST-STOP!” 

Papyrus pulled his hand away as if burned, face etched with concern.

“did i--?”

With a playful growl, Sans seized Papyrus’s arms and flipped them over. He pinned the lanky skeleton on his back 

“wha?” 

Not giving Papyrus the chance to reverse their positions, Sans swiftly wrapped his blue bandana around his sibling’s skull to cover his eyes.

“NOW IT’S MY TURN, PAPY! JUST LIE BACK AND LET YOUR BIG BROTHER TAKE CARE OF YOU!”

\---

Papyrus’s soul vibrated fiercely with hope. He’d always believed his more-than-familial love towards Sans had been disgusting. He’d spent numerous nights jerking off to the thoughts of taking Sans or vice versa. But this was Sans, his older brother, the only family he had left and had raised since they were babybones. 

Now, his fantasy had become reality.

Papyrus sighed as he felt clumsy phalanges drift down his ribs, to his sternum, and down his spine. The farther down the hands moved, the more confident their ministrations became. It was nice to be taken care of like the younger sibling for once.

Sans eventually reached Papyrus’s weeping cock and gave it a squeeze, making his breath hitch. The smaller skeleton then pumped his dick several times just as how he’d showed Sans minutes ago. With his sight gone, Papyrus could sense the frantic beating of Sans’s soul, could feel every minute movement his brother made, and could hear every moan that escaped from Sans and himself. 

“PAPY, I WOULD NOT BE WHO I AM TODAY IF IT WERE NOT FOR YOU. YOU ARE MAGNIFICENT!” 

Papyrus cried out when Sans brought their cocks together and jerked them both at the same time. His peak rapidly approached due to the praises and with his heightened senses.

“I LOVE YOU, BROTHER!”

He came screaming his brother’s name. Spurts of warm cum splattered onto his ribcage. The bandana was removed, and he saw both of their bones covered in a mix of blue and orange. But that hardly matter when Sans’s confession replayed in his mind.

“i love you to, bro. more than anything.”

And he was happy.


	15. Lap Dance (MobTale Papgore)

**Summary for the Chapter:**

> Asgore enjoys the company of a tall skeleton who works at a strip club. Although his moves are clunky, he never fails to bring a smile onto Asgore's face.

**Notes for the Chapter:**

> Think of this drabble as a possible prequel to before the skelebros join the mobtale family.
> 
> **Additional warnings: ecto-vagina, frottage, implied (forced) prostitution, implied non-con**

In Ebott City, the infamous crime ring, the Dreemurrs, owned half the city. They led the monster side of the city and fought hard against the injustices brought onto them by the human gangs. They only used deadly force when no other options exist. In that manner, they weren’t your standard mob. This was mainly thanks to the head of the gang, Asgore Dreemurr. His towering, intimidating physique drew fear in the eyes of the humans, though to monsters, he was their hope.

The said monster had a few particularities, especially after the bitter divorce of his wife, who chose to remain neutral on the human vs. monster gang war. One of such particularities was a strip club located within the neutral territory of Ebott City, hidden away in a grimy alley. He wasn’t there to look for sexual pleasure, especially since human patrons went to the establishment specifically for the unique experience of fucking a monster.

No, Asgore went there due to the company. The company of a tall skeleton whose sunny disposition brought light into his dark world. Papyrus was his name, and he truly was a gem in the environment he worked. How a monster like him ended up in this unsavory job frequently ran through his mind. Going to the strip club gave Asgore an excuse to keep an eye out for the young skeleton monster. There was many instances where he’d thought about adopting Papyrus into the Dreemurrs, but due to Papyrus’s gentle soul, he would always have second thoughts. 

As soon as the head of the club, Jerry, saw him enter, he went to fetch Papyrus. The bone monster wore a revealing spaghetti-strap shirt with black, tight pants that accentuated the elegant contours of his bones. Once Papyrus saw him, a bright smile flitted across his face, though the usual twinkle in his sockets were missing. Asgore frowned briefly and then led him into their private room. Asgore always requested a private room so they could speak without fear of eavesdropping and without interruption.

Asgore sat himself down on the plush, red sofa, and Papyrus straddled on top of Asgore’s thick lap. With a flicker of orange in both of Papyrus’s sockets, Asgore felt the skeleton’s ecto-flesh materialize over his bones. Papyrus ground against his crotch with the expertise of someone who’s recently started, which wasn’t far from the truth. But Asgore didn’t mind; in fact, he preferred it.

Papyrus swung his arms to wrap them around Asgore’s neck, bringing their faces closer. His breath hitched when Papyrus began to sway his hips against his lab, thrusting down in a rhythmic beat. The movement caused the front of his neatly ironed pants to bulge. His erection pulsed whenever he felt the covered folds of Papyrus’s pussy brush against it, wringing gasps from his lips. 

“You’re getting much better at this,” Asgore praised with a heavy pant, hoping not to sound demeaning.

Papyrus beamed and puffed out his chest in a prideful manner. 

“OF COURSE, THE GREAT PAPYRUS ALWAYS STRIVES TO PROVIDE THE BEST FOR HIS CUSTOMERS.” The skeleton deflated slightly. “ESPECIALLY SINCE I WILL SOON BE RECEIVING HUMAN CLIENTS LIKE MY BROTHER!”

The arousal pumping through Asgore suddenly halted at Papyrus’s words. Not only had he not known that Papyrus had a sibling, but the idea of Papyrus having to deal with the demands of humans made his soul quake. 

There was no way he could allow this to continue.

Asgore gently gripped Papyrus, stilling his sashaying hips. 

“Papyrus, do you truly enjoy working here?” The younger monster took a long time to answer; so long that Asgore added, “Because if you would prefer, I am willing to adopt you into my family. I am sure you are aware of my line of work.”

Papyrus stiffened and bowed his skull, directing his gaze at the grimy floor. 

Eventually, he replied in a subdued tone, “I mainly see monsters, so it is not a terrible life for me. Many of the monsters are very nice.” A smile of appreciation appeared on Papyrus’s mouth. “But I am aware that certain humans do not treat us, monsters… as nicely. And although my brother tries to hide it, I know he’s been having human clients for some time now and…”

Asgore heard a sob. Papyrus lifted his head, and Asgore's soul clenched in pain at the sight of big globs of orange tears trailing down his face.

“And I don’t know how much longer he can take it.” The skeleton took in a shuddering breath. “In truth, Mr. Asgore, I do not like working here. Not because of me, but because of how it affects Sans.”

There was another pause. Papyrus shook his head as though to clear it and gave Asgore a resolute look.

“THANK YOU FOR YOUR OFFER MR. ASGORE BUT I CANNOT LEAVE MY BROTHER TO WORK HERE ALONE.”

Papyrus got up from Asgore’s lap and turned around. Before he could walk away, Asgore seized his right wrist. 

He wished he’d known sooner. If he’d known that Papyrus had a brother, and that they both worked here, one of them even requested by humans, he would’ve asked months ago. But it was too late to dwell on what had already passed. 

“Then both of you should come. I’ll gladly accept both of you into the Dreemurr family.”

Papyrus’s entire face lit up into the brightest smile Asgore had ever seen on him, full of teeth and with sparkles in his eye sockets. In his joy, Papyrus embraced Asgore tightly, though even his long arms barely wrapped completely around Asgore’s bulky form. 

“YOU MEAN IT? YOU WILL ALLOW US TO JOIN YOUR GANG?! I COULD BECOME… YOUR BODYGUARD?!”

Asgore chuckled warmly and patted Papyrus’s back.

“We’ll see. For now, perhaps we should speak to the manager of this establishment about terminating both you and your brother’s employment here.”

“YES! I AM SURE THIS GOOD NEWS WILL LIFT SANS’S SPIRITS! WOWIE, MR. ASGORE, YOU ARE TRULY AS GENEROUS AS THEY SAY!”

“Hey, now, Asgore is fine.” He leaned closer into Papyrus to where his ears would’ve been if he had them. “Some even call me Fluffybuns, though please don’t make a habit of calling me that.”

Asgore led Papyrus, hand in hand, to the front register, wondering what new adventures these two skeleton brothers would bring to the Dreemurrs.

**Notes for the Chapter:**

> Oh look! Another drabble that may or may not become a longer fic. :3


	16. Wax Play (UF Sansby)

**Summary for the Chapter:**

> Grillby discovers a concerning habit of Sans's. He offers help to rectify some of it.

**Notes for the Chapter:**

> **Additional warnings: self-harm, masochism, ecto-penis**

Sans had a secret. One that he would take to his grave. 

He enjoyed pain.

He had this revelation about himself when he’d accidentally gotten a wood splinter stuck within his metatarsals after a scuffle with Doggo. The sharp jolt of pain felt like a breath of fresh air compared to the dull numbness he had fell into after realizing the resets had resumed. From then, he’d purposely get into situations where there was threat of injury but not death. It would take injuries from lethal intent to dust him, and he always made sure to avoid dangerous monster encounters.

It wasn’t as though he was purposely trying to get hurt, he reasoned to himself. It simply reminded him that ‘this was real’, that he could still feel, that _he was alive_.

Eventually, the minor scratches that he’d received from his sentry duties weren’t enough. With a chip here, a crack there, a new sensation had begun to fill him — arousal. Magic would rush to his cheeks and his pelvis with every new mark he drew.

It became a coping mechanism and habit that helped him stay grounded in the seemingly perpetual time shifts which occurred within the Underground. It was a temporary reprieve from his shitty reality.

Until one evening, after one to many mustard bottles, he’d unwittingly let his trademark, fur-lined black coat slip off his frame just enough for Grillby to catch the deep, jagged chips on his right clavicle. The next evening after the bartender had close down his bar, when Sans sober, he dropped the bomb.

“What’s wrong Sans?”

Sans furrowed his bone brows in confusion.

“whaddya mean, grillbz? nothin’s wrong.”

Grillby, knowing that dancing around the bush with regards to the topic of Sans’s well-being was like beating his head at a brick wall, stated bluntly, “Why are you hurting yourself?”

Sans’s ruby eye lights guttered out and his usual smirk grew strained. It took several long minutes for him to respond.

“look, bud, yer gettin’ the wrong idea. i just…” Sans’s eye lights reappeared and darted towards the recently-swept floor. “i enjoy the pain. i-it... it makes me feel alive.”

Silence.

“... It makes you feel… alive?”

At Grillby’s angry tone, Sans shrank into his jacket as though he would disappear into it. His magic surged in preparation for a shortcut when, without warning, his jacket was ripped off of his body, he was swept up and laid on his back on top of the bar counter. 

“grillby, what the fuck?!”

Sans flailed his arms to try and get away from the other, but the fire elemental simply caught both of Sans’s wrists in one hand and pinned them down above his head. Grillby’s purple flames expanded as he lifted Sans’s red shirt to expose his ribs and spine.

“Sansssss,” the flame monster hissed, literally. “If you wanted to experience enough pain that you would hurt yourself, you should’ve just come to me!”

“wha -- ah!”

Sans twitched violently in Grillby’s grip as thick, scalding liquid dripped onto his lower left floating rib. Before he could get a word out, another drop plopped on his next rib, sending a burst of blistering pain that shot straight through the bone. Soon after, it cooled and congealed, tingles filling the area where the liquid had landed. Sans lifted his head up to see that it was purple candle wax, and the source seemed to be from Grillby’s mouth. The bartender paused.

“Is there a problem? Do you want me to stop”

The contrast between the initial searing heat, followed by the soothing, cooling sensation, stimulated Sans like no other. He gave his consent, and Grillby continued. Sans’s moans filled the air as Grillby coated his ribs with spiraling designs, creating elaborate criss-cross patterns. To prevent Sans’s shirt from burning away, Grillby had shifted the article of clothing upwards and twisted it around his arms to keep them trapped above his head. 

By the time Grillby finished his design, Sans was a whimpering, moaning mess; tears beaded the corner of his eyes and drool trickled down his open jaws. The magic pooled around his pelvis had shifted into a weeping cock, twitching every time another drop of wax landed on his bones. Grillby increased the temperature of the wax when he reached Sans’s spine.

The burning heat, as smothering and painful as the lavas of Hotland, enveloped Sans in white hot pleasure, which became magnified by the cooling effects of wax. The further down it traveled Sans’s torso, the louder and more desperate his cries became. 

“hnnngh... gril… bz… so good… please… ah!”

Sans could barely move, not even to arch his spine, with how much dried wax covered his body. He could only lay helplessly on the table until Grillby finished. The dull warmth provided by the hardened wax edged him further, his mounting pleasure readying to snap. And snap it did when droplets of wax fell onto Sans’s erection. He came with a wail, spurts of red cum spattering unto his own wax-covered ribcage, painting the normally white canvas a mix of red and purple. Some of it even hit Grillby, resulting in sizzling.

Sans lay on the table, panting raggedly. As he came down from his orgasmic haze, he felt Grillby wipe off the hardened wax. Sans shivered on the bar counter. As the bar owner’s calming strokes continued, Sans’s eyes drooped. 

“Sans!”

The urgency in Grillby’s tone snapped his sockets back open. 

“yeah, grillbz?” he answered groggily, and snuggled into the bartender’s leather jacket.

He had somehow fallen into the fire monster’s comforting arms. Most of the wax had been cleaned off his bones, and his arms were finally free, though his shirt was missing.

The fire that made up Grillby’s head turned orange. It looked like his version of a blush.

“You know I care about you, right?”

“‘course, grillbz.”

“So the next time you feel the need to hurt yourself, will you allow me to do this for you?”

“heh, sure. but i’m not gonna off myself, grillbz, if tha’s what yer worried ‘bout.”

“But I do worry, Sans.” Grillby’s embers crackled. “I may not know what you’re going through, but at least let me help you.”

Sans was touched at Grillby’s concern, and it brought a prickling sensation to his eyes. It was so rare for another monster to offer help in their kill or be killed universe, let alone Grillby of all monsters. He’d always been known to be a hardass; but then again, the flame monster also always had a soft spot for him, being Grillby’s favorite customer. And Sans definitely didn’t mind his company.

“a’right, pal, i’ll take up yer offer.”

**Notes for the Chapter:**

> I'm gonna take a few days off from updating. I'm starting to feel burnt out from daily updates so if my updates begin to slow, that's why. But thanks to those that've been reading and comment (especially you, sesu! <3)!


	17. Massage (Asgore x Gaster)

**Summary for the Chapter:**

> Gaster gives Asgore a massage. It gets heated. Thankfully Gaster has a few extra _hands_

**Notes for the Chapter:**

> **additional warnings: hand-job**

_BOOM!_

An ear-shattering explosion resonated throughout the underground laboratories where Gaster worked. When the smoke from the blast cleared away, he was muttering furiously at his poor assistant to jot down everything that went wrong with his latest experiment. Nevermind the fact that the poor green lizard monster could hardly keep up with Gaster’s rapidfire demands.

In midst of his manic rant, a Royal Guardsman stopped by to deliver a message on behalf of King Asgore. Apparently, he had been summoned.

Gaster sighed as he rode the elevators up into the sweltering heat of Hotland. He signed rapidly in wing dings, _that old coot’s probably feeling lonely again, and will waste more of my precious time._ His movements were jerky and agitated. 

Gaster only signed when he didn’t want others to hear his rants about the King. Although Gaster respected Asgore a great deal, whenever the old goat got into one of his _slums_ , he became annoyingly clingy and needy towards Gaster. Gaster didn’t have a huge problem with that except for the fact that it interfered with his work!

By the time he reached the throne room, he had calmed down and his rude gestures had ceased. Asgore stood with his back turned away from the entrance, his attention caught by the golden flowers in the garden. A pang of sympathy pulsed within Gaster’s soul, and regret filled him from his earlier criticism towards the King.

When his wife, Calibri, died, Asgore had been so kind and supportive. Shouldn’t he return the favor?

Two incorporeal, floating hands, each with a hole that matched the same one at the center of Gaster’s own palm, materialized in thin air and floated towards Asgore. Using the minute amount of golden light that filtered into the throne room, his hands created shadow puppets on the walls directly in front of Asgore. It depicted the comical scene -- in Gaster’s opinion -- of a rabbit monster trying to start a fire but set himself on fire instead. The scene must’ve been lost on Asgore, as the King didn’t even chuckle. Gaster frowned and tried a different approach, one that his late wife used to do to him after he’d been working for long hours. 

Two glowing palms settled within the juncture where Asgore’s neck and shoulders meet and pressed firmly down. Asgore startled, his entire frame shaking. Gaster sent pulses of purple magic as he rolled the tense trapezius. Once loosened, the palms made broad strokes down Asgore’s shoulders. 

“Wait, Gaster.”

He paused and directed his attention at the boss monster. The white fur and yellow mustache lining Asgore’s face were tinged in a pink blush.

“P-perhaps it would be best if we took this to more private quarters.”

Gaster nodded. “Indeed. It would be disastrous if I were caught fraternizing with the King, even if you are divorc-”

Gaster cursed at his inopportune foot-in-mouth syndrome, especially at the sight of Asgore’s utterly devastated expression.

“Come, allow me to provide you with some company,” he attempted to rectify.

Thankfully, Asgore snapped out of his despondent haze and led the two of them into the master bedroom. As soon as the doors were locked, Gaster ordered Asgore to remove his the armor and lie down on his front on the bed.

Gaster had a particularity when it came to touching others: he didn’t. With his detachable, multi-purpose hands, why would he need to touch others?

He stood off to the side while he got his _handy_ assistants to work. The two that had been massaging Asgore’s back got back to that assigned duty while two others disappeared into the bathroom to grab some magic-infused oils. Gaster poured the oil onto the King’s furry back and had the two palms spread the liquid until a thin layer covered Asgore’s back. The hands rocked back and forth, rolling and lifting at particular muscle groups, and drew harsh, circular movements. Asgore sighed in relief, body growing limp.

“That feels… really good.”

Asgore hummed when the second pair of hands kneaded upwards from Asgore’s feet and ankles. As they traveled further towards the goat monster’s toned ass, Asgore’s breath grew heavy, almosting panting, and he began to rut against the bed. 

Gaster had to admit, the sight of Asgore’s naked body, with all its toned muscles from years of training, was arousing. He had never been this intimately close with the King until now. 

“Can you do my front as well?” 

Gaster stared, heat rushing to his face.

He cleared his nonexistent throat and answered, “It would be my pleasure.”

When Asgore flipped over, his hard cock caught Gaster completely by surprise. The member was long and thick; thick enough to fit through the hole in his hand.

A (brilliant) idea rushed into Gaster’s head.

“Do you need some help relieving that, your majesty?” Gaster indicated at the erection.

Asgore attempted to cover it with his paws, but the disentangled hands stopped them before they could.

“Do not be shy, Asgore,” Gaster intoned. “Allow me to give you a _hand_.”

A surprised chuckle escaped from Asgore’s mouth, and he nodded.

As though operated by an ‘on’ switch, three hovering hands increased the pressure and ferocity of their massages. The final one wrapped around Asgore’s dick and pumped it several times. Thin fingers teased the head, and pre-cum beaded at the slit. Low groans and throaty growls filled the room. 

Meanwhile, Gaster dabbed oil around the edge of the hole carved in his left palm. Once completed, he brought the hand to Asgore’s cock and inserted it. The head almost got stuck, but with a shift of his palm ten degrees counterclockwise, Asgore’s dick slid through. The edges of the hole scraped lightly against the flesh. Gaster moved his hand up and down Asgore’s length as the King thrusted to meet his movements. Three pumps later and ropes of cum spurted from Asgore’s cock, coating Gaster’s hand in the white  
Iiquid.

Gaster pulled his hand away with a wet squelch. He shivered in barely suppressed disgust at how dirty it all was. He couldn't wait to disinfect it when he got back to the lab.

“Thank you, Gaster. I have been feeling down lately, and although this doesn't solve my problems, it does help. I don't know what I would do or what I would be without your support.”

“You helped me through my tough times, so it's only fair that I return the favor.” Gaster took out a handkerchief to wipe the cum off his hands. “If you’ll excuse me Asgore, I must head back.”

“O-oh yes, I shall let you go back to your Royal Scientist duties. Though I have one question, Gaster. Why do you only have a hole in your left hand?”

Gaster did not answer for several seconds before his toothless mouth curled into a wide grin.

“I’m afraid that is a secret, my King. Someday, you will know.”

Asgore seemed content with the answer, and Gaster took his leave. After all, he had a babybones to take care of.


	18. Masturbation and Daddy Kink (Vamp!Gaster x Papyrus)

**Summary for the Chapter:**

> Papyrus is enchanted by his brother's new boss.

**Notes for the Chapter:**

> Blegh, this chapter stumped me for so long, and I'm still not too fond of how it came out. Then again, daddy kink isn't all that appealing to me so I apologize if this came out lackluster. Also, the vampire aspect is only hinted.
> 
> **Additional warnings: pillow humping, ecto-vagina, vagina fingering, biting**

There was something alluring about Sans’s new boss, Gaster. Papyrus first met him when Sans had invited the older man to their house for dinner. His imposing, yet elegant stature, with his pale skin, drew Papyrus like moth to a fire. Papyrus couldn’t discern if Gaster was a flesh-based monster or strange skeleton-humanoid hybrid. He was also so polite and very kind, giving so much attention to him. For Papyrus, it was nearly love at first sight.

Then, one day after work, Sans announced that Gaster wanted to adopt them as their sons, and have them live with him. Although Papyrus had been ecstatic, and voiced his agreement many times, Sans had been more hesitant. Gaster had been more than willing to give them time and space to make the decision. To do so, he invited them over to live with him every weekend, and Papyrus took the opportunity to spend as much time with the scientist as possible.

And the more time he spent with Gaster, the more his attraction grew. So much so that, as soon as Papyrus arrived at Gaster’s mansion in New Home, he rushed to the older monster’s bedroom. He had arrived first, hoping to relieve some of his pent-up frustration. His fantasies about Gaster had only grew more and more inappropriate over time.

Feeling equal parts shame, excitement and anticipation, Papyrus leapt onto Gaster’s simple but large bed, picked up one of the firm pillows placed by the head of the bed, and breathed in his scent. It smelled of ozone, sweetly scented soap and ink, and it was wonderful. He imagined Gaster, _their father_ , wrapping his long arms around him, enveloping him in the other’s scent. 

Papyrus shivered, and heated magic pooled at his pelvis. He slipped his right hand into his shorts and twirled his phalanges within the magic, imagining Gaster’s cold, elegant fingers. It quickly morphed into a slick mound. Papyrus sat up and mounted the pillow in between his femurs, pressed up right against his soaked pussy and squeezed it tightly between his legs. Except it wasn’t enough. Not without the real person. If only the pillow were Gaster’s head, Papyrus would’ve been on cloud nine. 

What would Gaster’s tongue be like? And when had he become so shameless as to pleasure himself on his brother’s boss’s -- their dad’s -- pillow! 

He rutted furiously against the cushion, his sockets closed. Loud cries and moans of pleasure flowed out of his mouth.

“Papyrus?” a deep, soothing voice exclaimed.

“DADDY!”

When Papyrus realized who had just called out his name, his face burned so hot that he thought his skull might melt. The man himself, Gaster, the scientist, his daddy, stood in the doorway with a bemused expression, though a hunger twinkled in his eyes. He slowly and smoothly stalked over, much like a predator towards its prey, Papyrus backed up until his spine hit the wooden headboard.

“Papyrus,” he began easily. “Have you always felt this way about me? Why didn’t you say anything earlier?”

“BE-BECAUSE YOU ARE MY BROTHER’S BOSS, AND I DID NOT WANT TO POTENTIALLY CAUSE TROUBLE.”

Gaster’s pale hands gently cupped Papyrus’s cheek, who flushed a deeper shade of orange. 

“You need not to worry about Sans’s employment with me, though it is so considerate of you. It’s why I find you so attractive, Papyrus.” Gaster pulled his face close to his own, their faces inches from each other. “Would you like daddy to pleasure you, Papyrus?”

The low, seductive tone had Papyrus completely enchanted, and he nodded without hesitation. Gaster pressed his lips against his teeth. Gaster’s icy lips felt wonderful against his teeth. The scientist’s tongue darted out, swiping against his teeth, and Papyrus parted his mouth to allow entrance. As they kissed, a hand slid into his short to finger his summoned pussy. Papyrus gave a muffled mewled when the digit curl against his inner walls. Gaster pulled away from their kiss, a string of saliva connected their tongues, and broke apart. 

“You’re so youthful and lively, my boy. I’m so proud.”

“THANK YOU,” Papyrus panted. “YOU ARE QUITE ENCHANTING YOURSELF... DADDY.”

Gaster chuckled, the airy quality sending butterflies to flutter within Papyrus’s nonexistent stomach.

“Though you’ve been a naughty boy for entering my bedroom without my permission. Daddy will have to _punish you._ ” As Gaster uttered those final two words, he pressed firmly against Papyrus’s clit, wrenching a keen from his mouth.

Excitement flooded Papyrus’s soul, and the pressure coiling within his lower half felt ready to burst.

“THEN PUNISH AS YOU SEE FIT, DADDY!”

Gaster plunged a second finger into Papyrus’s ecto-vagina and scissored the opening. The older monster leaned his face into Papryus’s gleaming, white neck, and licked his tongue along the cervical column, forcing more lewd noises from Papyrus. 

Papyrus wailed when, without warning, sharp fangs sink into his bones, and he came hard against Gaster’s plunging hand. His magic seeped out from the bite wound. He became limp within the scientist’s embrace, and everything seemed to fade away into darkness.

When Papyrus came to, he was laying in a large, soft bed. He sat up, feeling strangely weak, and realized he was in his own bed, wearing a fresh set of pajamas. Flashes of his earlier escapade with Gaster came back, and he blushed at the memory. 

With a soft click, the door to his room swung open to reveal his brother. A bright smile adorned Sans’s face.

“hey, pap, i’ve decided to accept gaster’s proposal.” 

Footsteps sounded in the hallway. 

“guess we should start callin’ him, dad, huh.”

Gaster stepped inside with a knowing smile.


	19. Part I: Latex and Face-sitting (Soriel)

**Summary for the Chapter:**

> Toriel wants to provide her skeleton lover a good time.

**Notes for the Chapter:**

> This was originally day 8's themes (I had switched it if you remember).
> 
> Also, in case my description wasn't clear enough, the sacrum lacing is based off [THIS FANART](http://xxblood-red-ravenxx.tumblr.com/post/147119869895/ribbon-bondage-it-is-life-request-for). I made a few changes in the chapter though. Also, thanks to [Mercy-run](https://archiveofourown.org/users/Mercy_Run/pseuds/Mercy_Run) for the info about subspaces. 
> 
> **Additional warnings: light dom/sub, cunnilingus, sacrum and spine lacing, light bondage, entering subspace**

Toriel’s soul did somersaults within her chest as she pulled on the skin-tight black suit and zipped it up to her ample bosom. It wrapped snugly around her entire body like a second layer of skin. She stared into the full-length mirror and flushed lightly at her own reflection. 

The midnight-colored latex accentuated the wide curves of her hips, her thick thighs and large breasts that were usually covered by her school-teacher attire. The suit almost covered her entire body, save for her head and a slit at her crotch that displayed her plump folds. Toriel wasn’t a vain monster, but this instance was an exception.

She looked great. 

She also knew both of her partners would appreciate it as much, if not more, than her. And sure enough, when she stepped back into her bedroom where Sans sat, naked and waiting nervously on the king-sized bed, a pair of wide, white eye lights automatically drew to her. She thought, for a split second, that they flickered into hearts. Toriel sashayed her hips as she made her way to the bed until she stood in front of it, not yet getting on. 

“tori,” Sans breathed. “ya look- look amazin.”

A soft cyan glow adorned his normally white cheekbones, and his arms twitched, rising and falling down as though he wanted to touch her but wasn’t sure if he should. Sans’s hesitancy made her smile warmly.

“I will allow you to touch me.”

Jittery hands lightly stroked along the side of her curves; the muted sensations from the latex wracked her form with shivers. She gasped when two phalanges brushed over her nipple. They immediately snapped away. Guilt affixed Sans’s face. 

“You did nothing wrong, Sans. It felt good. Keep touching me.”

With the confirmation that his touches were pleasurable, the petite skeleton resumed his ministrations. Toriel tried not to frown. Even after dating her and Asgore for half a year, Sans was still cautious, still so unsure, of everything he did with them. His tendency to forgo his own pleasure at their expense also remained unchanged. Which was why, for tonight, she and Asgore had control. It took several weeks of convincing Sans, but he’d eventually agreed. Toriel wasn’t going to waste this opportunity to show just how much she loved and cared for him. And she was sure Asgore felt the same way.

Toriel grew wet at the idea of wrecking Sans with pleasure and at the stimulation her nipple received. A particularly hard twist of the perked nub stole her breath away. She squeezed her legs together in an attempt to calm the throbbing of her pussy. 

“need some help with that, tori?” Sans asked, quirking his bone brows at her puffy slit. 

Toriel knew from experience that Sans would refuse everything she and Asgore had planned for him if he didn’t give first. 

With barely any hesitation, she answered breathily, “Yes, please!”

“it would be my _pleasure_ , heh.”

Sans was about to slip his bony fingers inside her when she stopped him. Although fingering felt great for _her_ , it did next to nothing for Sans. 

“I have a better idea.” Toriel brought her face close enough to Sans’s skull that her fur tickled its surface. She dropped her voice to a huskier tone. “How would you like to taste me?”

And there it was again. The flash of hearts in his eye sockets.

“yes, tori!” 

“Please lie down on your back in the center of the bed.”

Sans did as he was instructed. Toriel then climbed onto the bed, squeaks coming from her latex suit. She crouched over Sans’s skull with her facing his feet and lowered her pulsing heat over his face. After a few seconds of adjustment, she felt something slick and spongy dart inside her soaked channel. They curled along her walls, swiping back and forth within her pussy. She moaned lewdly. Through lidded eyes, she saw Sans’s toes curl inwards towards his ankles as his tiny hands clenched against the slippery latex wrapped around her thighs. 

“Th-this feels wonderful! You are doing so well!” 

The tongue plunged in and out of her pussy with increased fervor. Before long, Toriel had her sex pressed firmly on top of her lover’s skull. In midst of her blissful haze, she wondered if skeletons could suffocate without lungs. The thought utterly fled out of her mind when Sans’s tongue twirled her swollen clit. She came with a low growl of his name, and squirted. After taking several deep breaths to bring herself back down, she lifted herself from Sans’s face and turned to face him. Her soul gave a violent throb.

Despite the cum covering half of Sans’s face, he was completely out of it, his eye lights dilated and fuzzy. His blue, ectoplasmic tongue hung out of the corners of his mouth. 

“so good… t-tori,” he mumbled. 

There was no doubt in her mind that she would lose him soon, probably by the time Asgore arrived.

Toriel reached over the bed to swipe a wad of tissues from her nightstand and carefully maneuvered the dazed skeleton so that his head rested against her lap. With great tenderness, she began to wipe away the evidence of her recent orgasm, singing praises at him. He became limp, and his sockets lidded as she carefully wiped the cum away..

“Are you ready to continue?” 

Sans gazed at her with adoration and nodded. Toriel bent down to reach under the bed and brought out a dark box. From inside, she grabbed a spool of blue silk ribbons, and a plastic needle. She set them aside on the bed. Toriel laid Sans on his front, with his ribs supported by one of the large pillows. 

“I’m going to thread the ribbons down your spine and sacrum. Remember, if there’s any moment you feel uncomfortable, you are to use your safe word and signal if you can’t speak.” 

“ok. i promise.” 

Toriel unwound ten feet of blue ribbon from the spool and folded the length in half at the middle. Starting from the first thoracic vertebra, she threaded each end of the ribbon through the spaces between each side of Sans’s back ribs, crossed them over around his spine, and worked her way down. Each time she pulled the ribbon taut, the noises escaping from Sans’s jaws increased in volume. 

By the time Sans’s spine had been completely laced in blue silk, the younger monster was moaning and panting without abandon. But Toriel wasn’t done yet; she still had his sacrum. She had to use the plastic, blunt end of the needle to get the ribbon through the holes. She made sure she didn’t accidentally injury him, even if the end was blunt. Every twitch from Sans brought out more violent tremors from him, no doubt from the smooth sliding of the ribbons.

“How are you holding up, Sans?”

The skeleton only babbled some incoherent words, and nodded his head. Toriel kissed the top of his forehead.

“You are doing so well. Just a bit more.”

She resumed threading the remaining foot of ribbon in a criss-cross pattern through Sans’s sacrum. After she tugged the ribbons firmly through the last set of holes, wrenching a mewl from him, she forced his wrists behind his back and twirled the silk material in between the ulna and radii of each wrist to tie them to his laced-up sacrum.

Every movement Sans attempted to make, like arching his spine or pulling against his bindings, shifted the ribbon through his bones. He whimpered at the continual onslaught of pleasure. Toriel settled a paw on Sans’s skull and began to draw soothing strokes.

“It is all right, Sans, let Gorey and I take care of you. You have nothing to fear.”

As if her words had been a magical chant, the door to her bedroom swung open. At the same time, Sans’s eye lights morphed into hearts. This time, they remained.


	20. Part II: Threesome and Pet Play (Sansgoriel)

**Summary for the Chapter:**

> Asgore, Toriel and Sans all have a good time.

**Notes for the Chapter:**

> **mild pet play, penetrative sex, subspace, soul sex, aftercare**

Two things caught Asgore’s attention as soon as he entered the room. The first was the skin-tight outfit his former wife, and current girlfriend, was wearing. Even after all these years, he still found her absolutely stunning. The latex suit definitely brought out her wonderful curves. She was crouched over the prone form of the second monster that he loved — Sans.

Silk, blue ribbons decorated Sans’s spine and sacrum, the delicate and lovely design no doubt done by Toriel. With his wrists trapped behind him, Sans was completely compliant to Toriel’s gentle petting of his flushed skull. Dazed, heart-shaped eye lights shined brightly within the black pits of Sans’s sockets.

“Sans? It is me, Asgore, I have arrived,” Asgore announced.

At the sound of his voice, Sans startled and attempted to turn around. Like a series of pulley systems, the ribbons slid through his bones and pulled taut. Sans whimpered.

“We need to be careful, Asgore,” Toriel warned. “In Sans’s current state, he is extremely impressionable.” She tenderly stroked a clawed finger down the side of his face. “Aren’t you, dear?”

Sans leaned against her paw in response and nodded. Asgore stripped off his shirt and pants as he walked to the bed, and dropped a sack onto the floor next to it. 

“Do you mind if I have a bit of fun with him, Tori?”

“Go ahead. My fur needs some air, which it isn’t getting with this suit.”

Toriel stood back up with a squeaking sound.

“It looks amazing on you, dear.”

A pink blush colored Toriel’s snowy fur. She giggled and went back into her dressing room. Asgore turned to find Sans squirming on the bed with a cyan pool of drool forming in the sheets where his mouth was. Asgore cooed softly as he scooped the small skeleton into his arms, careful not to jostle the ribbons too much, and pressed Sans against his warm, fuzzy chest. He gave a high-pitched mewl.

“I’ve got you, Sans, don’t worry.”

Asgore sat down on the edge of the bed and opened the bag that he brought. Various toys and accessories filled the bag. Some of it was old, dating back to his and Toriel’s younger years. He pulled out a blue collar with a tiny bell attached to it. Sans jerked his head towards the sound of its jingle. 

“Ehehe, this is a silly old kink of mine, but would you allow me to put this on you?”

“yes… pl-please,” Sans moaned. 

Asgore undid the buckle and slipped the collar on. He then placed a pair of white cat ears on Sans’s skull. Just as he finished, Toriel stepped back into the room wearing nothing but a black, sheer lingerie top that draped over her shoulders but still exposed her large breasts. 

She ambled over, straddled Asgore’s lap with her arms wrapped around his neck and kissed him while keeping Sans trapped between both of their warm bodies. Pleasure spiked within Asgore as he felt Toriel grind down on his clothed member. Their tongues wrestled, twisted and curled within their opened snouts, making him feel heady. Meanwhile, he heard heavy panting from Sans due to the constant shifting of silk and tickling of fur. 

When Toriel pulled away, Asgore saw a blue glow shimmering from within Sans’s ribcage — his soul. Just as he was about to touch it, Toriel stopped him with a paw.

“Not yet, Gorey.”

“Golly, you’re right, Tori. It would be bad to rush this.”

Asgore handed their youngest and smallest lover to Toriel and leaned his back against the headboard. Toriel freed Sans’s wrists, but kept the lacing in place. She positioned Sans on his hands and knees on the bed, his limbs quivering from the stretch of the silk wrapped around his bones. The wrecked expression on Sans’s face, along with his heart-shaped pupils, set Asgore’s soul alight. His cock was achingly hard, and he removed his sunflower-design boxers to free his erection.

“Be a good boy, Sans, and come to me. I’ll tell you when to stop.” Asgore ordered in a gentle tone.

Slowly, and with a jingle with every movement, Sans crawled three steps over to him until he had Sans stop in front of his thick cock. Without having to say a word, the skeleton automatically swiped his ecto-tongue down the length, leaving a trail of saliva. A low rumble echoed from the depth of Asgore’s throat as Sans teased his head. Three licks later, Sans grabbed the base of his cock and sank his mouth on top of it. Asgore barely held back the urge to ram his dick straight down Sans’s throat. He petted the top of his lover’s skull not dissimilar to how he would a cat.

“You’re doing such a wonderful job, Sans.”

The praise had Sans sinking Asgore’s dick all the way down his conjured throat. The tight heat drew a growl of pleasure from Asgore. He snapped his attention to Toriel when her breaths grew heavy. He saw her jab three fingers in and out of her soaked pussy while her left paw twirled her erect nipple.

It was getting too much; he was too close.

“Stop,” he uttered. “That’s enough, Sans, thank you.”

Sans withdrew his mouth with an audible pop, and gazed back at Asgore, waiting for the next command. Asgore’s paw wavered over Sans’s ribcage.

“Will you allow us to handle your soul, Sans?”

There was a brief pause, and then a brilliant glow flooded the room. When it faded, a white inverted heart floated before Sans. Asgore cupped the soul, it’s tiny size engulfed completely by his large paws. He stared at it with reverence, the white organ gleaming the light blue of Patience.

“It’s beautiful, isn't it, Tori?”

“Indeed, Asgore, it’s just as wonderful as our over-so-kind and wonderful Sans. We both love you and want to show you how much we do!”

Sans’s face became a blueberry. “i... i too…”

Toriel turned to Asgore. “Are you ready, Asgore?”

“More than ready, Tori!” 

Asgore released Sans’s soul to allow it to hover between all of them. Toriel lifted Sans up and laid him down on Asgore’s chest. She then adjusted herself over Asgore’s throbbing length and sank down. Both of them moaned at the sensation. She lifted herself off and, as she came back down, Asgore snapped his hips up to meet her thrusts. Once they set a steady rhythm, Asgore resumed his petting of Sans’s skull, while Toriel danced her claws lightly over the ribbons decorating his sacrum. 

Two more bright flashes suddenly lit up the room. Two additional souls materialized into the air. His and Toriel’s souls were slightly bigger, a quality of boss monsters, and pulsed purple and yellow, respectively. The larger souls circled around the smallest one, slowly drifting closer to each other until they were centimeters apart. At this distance, all emotions were exposed; not only their appreciation, happiness and love for Sans, but also their overwhelming pleasure. 

The three souls melded together, the slick liquid magic mingling together like a painting. The shared sensations were too much. The room flashed a brilliant shade of blue, green and purple light. The magic released from their souls splattered over all three of them. Both he and Toriel nose-nuzzled either side of Sans’s cheeks. Toriel then laid him down on his front to undo the ribbons laced around Sans’s vertebrae and sacrum. As soon as they were removed, Sans stretched out his back and fell limp. The cat ears and collar came off last.

“I’ll prepare something for when he comes back to us,” Toriel said.

Asgore pulled Sans into his arms. He made sure to breath slowly to help bring Sans out of his subspace. He also grabbed some tissues from the nightstand and began to wipe the excess magic dripping Sans’s bones. The younger monster shivered. Asgore draped a thick blanket and comforter over the two of them. Eventually, his eye lights flickered back into their normal, round dots. 

“How are you feeling, Sans?”

“... _bone_ -tired.”

Asgore chuckled warmly. “You are free to sleep as long as you need. “

“But not before you eat something, dear,” Toriel chimed in. 

She back into the room with a glass of water and a chocolate bar drizzled with ketchup. Sans’s pinpricks brightened at the sight of the red condiment and nearly swallowed the chocolate whole. Toriel made sure he finished the glass of water, and then snuggled into bed with him sandwiched between her and Asgore.

“We love you, Sans,” they both said.

Sans’s permanent grin lifted into a genuine smile.

“i love you too, both of you.”


	21. Impact Play (HoneyMustard)

**Summary for the Chapter:**

> Red provides Stretch the _impactful_ play that he seeks.

**Notes for the Chapter:**

> **additional warnings: ecto-flesh, ecto-cock, chains, restraints, implied Swapcest, “improper” use of blue and orange bone attacks.**

Clinking sounds filled the cold, dank secret lab room. Papyrus, who typically went by the nickname Stretch — given for his lanky stature — shifted in his shackles. He hung, face against the wall, from chains attached to each of his wrists. He could sense the hum of Red’s magic, the skeleton standing a foot away from him. 

“summon somethin’ fer me ta smack or this’ll hurt like a bitch. heh, not that it won’t already i mean,” Red’s ordered in a deep, gruff tone. 

Papyrus’s phalanges clenched and unclenched in his shackles, and sweat beaded the top of his skull. With a flash of orange and cyan from his right eye, translucent ecto-flesh formed over his bare pelvis and femurs. His breath hitched when he felt the other skeleton grab one of his buttcheeks and give it a firm squeeze. 

“that’s one nice ass ya got there, stretch.”

“wouldja give these _honeybuns_ a test?” Papyrus couldn’t help but tease, waggling his bone brows, despite his compromising position.

“is that a challenge?”

Without warning, something cold and hard smacked his ecto-ass. Papyrus gasped sharply as the hit seemed to rock his entire frame, sending shockwaves of pain throughout his body. It shot straight to his soul. 

And his HP dropped by 1. 

Before he could brace himself to consider what had occurred, another loud smack echoed in the chilly room, this time far harder than the last. 

Another 1 HP lost. 

The chains clattered together as Papyrus groaned and squirmed within his bonds. A yelp finally escaped his jaw when another strong hit landed during his floundering. This dropped 2 hit points. The searing effect from before was even more pronounced, and his magic buzzed within his bones, pooling down to his pelvis to form a hardened shaft.

“wow, ya must be really enjoyin’ this, huh?”

Papyrus tried not to move, and was greeted by another clip with the same intensity as the first hit. He finally peered behind him and saw that the shorter, red-clad skeleton had two scapula bones summoned in each hand; one of them was blue and the other was orange.

“better keep movin’, bud, if ya don’t wanna hurt more,” Red warned as he swung the blue-colored bone.

“ah!!” 

It felt as if Asgore had rammed his horns against his ass. Tears sprung out in the corner of his eyes.

 _SMACK!_ Another blue attack.

Papyrus shifted.

_SMACK!_

He was too slow to evade the orange attack.

Back and forth, Red alternated between blue and orange attacks, sometimes even switching the pattern up. With each hit, Papyrus’s dick twitched and became harder. By the time Red finally gave him a break, pre-cum dribbled out of his slit, and his HP was down to 665.

“geez, never figured ya be into this sorta thing.”

“heh, i can’t ask sans to do this sorta thing with me,” Papyrus said.

Guilt always tinged Papyrus’s soul at the fact that his masochistic tendencies required relief by either Red or his brother. He couldn’t request this sort of activity with his brother, considering Sans was too innocent and couldn’t hurt a soul, let alone his own brother.

“it’s a good thing the sanses hp stat didn’t pass t' ya.”

“yeah, guess i got lucky.” Bitterness tinged his tone.

“hey, don’t feel bad. all us sanses have survived this long. ‘m sure yer bro’s just as good a dodger as any one of us.”

Papyrus nodded and let his mind clear. As soon as it did, another blow met him. At some point, the buzzing pain and pleasure that vibrated within him became too much, and his seed splattered onto parts of the wall and the floor closest to where he stood. Papyrus shivered from the aftershocks of his orgasm, made worse by the surprisingly soft caresses Red ran down his bruised ass.

Red unlocked the cuffs around his wrist, and he slipped onto the floor like a stringless puppet. A second later, Red was at his side, helping to support his slumped form. Just as Red was about to hand him a spider cookie to heal his bruises, the door to his lab-turned-playroom swung open. 

“PAPY! THERE YOU ARE! I DIDN’T KNOW THIS LOCKED SHED LED TO SOMETHING LIKE THIS!” The short, blue Sans puffed out his cheeks, his star-shaped eye lights brightening. “WHY WASN’T I INVITED?”


	22. Scars and Collaring (Reborntale Kustard)

**Summary for the Chapter:**

> Red's peace is interrupted by a fallen angel. Literally.

**Notes for the Chapter:**

> **additional warnings: none (this is pretty SFW)**

Red lounged around in his lair, reading through a paperback book with a clown on the cover. He chortled at how pathetic the humans depicted in the novel were. He normally held contempt for any human-produced works, but if there’s one thing they got right, it was these “horror” genre of books.

He was halfway through a death scene when a pig demon greeted him. A stampede seemed to follow behind him.

“what’s all the ruckus?” Red growled.

Ever since his brother had been promoted higher on the demon ladder — with him following suit due to their relationship — Red had gotten disturbed more than he’d like for the most mundane things. Then again, he was second-in-command of the Fell territory; it was his job to take over whenever his brother was away. 

“Sire,” the pig demon gave a low bow. “An angel has landed outside the entrance of your and Lord Fell’s territory.”

Red perked up with interest. It wasn’t every day an angel fell into his land.

“Furthermore, he’s special.”

“whaddya mean?”

“He’s Fallen, sire.”

Red sprang up from his seat, his black, skeletal wings stretching out at their full size. They dwarfed his own stout, big-boned (heh) stature.

“lead the way. can’t let ‘em other demons take what is mine!”

The two rushed through the fiery, dark depth, up towards the entrance of the Fell demon lair. The hum of magic hung thick in the air, and the battle cries grew louder as he drew closer to the mouth of the cave. 

Stray bones hurtled towards him, which he easily knocked away. He came upon a petite skeleton surrounded by five lesser demons. Red’s breath caught in his throat at the state of the other’s wings. Bat-like membranes and spines already replaced the ethereal feathers that should’ve occupied the top half of the skeleton’s left wing while the bottom remained in its angelic state. But it was the right wing that captured Red’s attention. A grievous tear ran diagonally down the length of the wing, soaking the normally white feathers in liquid cyan magic. 

A high-pitched whine snapped Red out of his trance, and three draconic skulls suddenly hovered in the air. Each one shot out blasts of concentrated magic, instantly vaporizing three of the demons. The remaining two hellhounds charged towards the angel, who collapsed onto his knees. Just as the hellhounds raised their claws to attack, Red grasped their souls in his sharp phalanges and clenched down on them. They dissipated into dust.

Red turned his attention to the angel, noting the cuts and chips that littered his face and the exposed portions of his arms and legs. Sweat poured down his skull, and dark lines of exhaustion marred his face. As Red sauntered closer, the other attempted to summon a bone attack. He was admiring the angel’s magical fortitude when a howl resounded in the distance, no doubt signaling more demons to come. 

“sorry, sweetheart, but this is fer yer own good.”

“wha—?”

Without warning, Red appeared in front of the small skeleton, took ahold of his soul and pressed his claws lightly against it.

_Sleep!_

His intent broke through, and the angel crumpled limply into his arms. Before the other demons arrived, Red took a shortcut into his room. He laid the unconscious skeleton down on his front, taking care to not further tear the wing injury that was still profusely bleeding blue magic. It would scar, and the scar would likely remain even after its complete transformation into demon wings. 

But for now, Red could appreciate the light, pearly feathers. He wondered if he could touch it now that this angel had Fallen. He brought up a hand and stroked tenderly through it, feeling the smoothness and its airy quality. A shudder ran through the unconscious monster, causing Red to stop. He experienced no pain when he touched the wings, which confirmed that they had lost their protective — and anti-demon — properties.

What could this angel have done to Fall? And be in such a state when he did? He must’ve broken one of Asgore and Toriel’s cardinal rules. But to leave him in such a wounded state to fend off against demons and human Slayers? That was a shitty thing to do. It was lucky for him that Red found him first instead of someone worse.

Red turned from his bed and eyed his partitioned storage closet. He had to make sure the other demons knew this Fallen belonged to him, both as a means of protection and because the idea sent excited tingles down his spine. He dug through his belongings until he found a plain, black collar. It would have to do for now. 

Red approached the former angel and startled when the other’s eye sockets blinked awake. He attempted to get up, and his white eye lights constricted into pinpricks when he saw Red.

“whaddya want, demon? stay away!” His voice shook despite the hostile tone.

Red grinned widely and approached at his full height. The angel shrank back slightly. 

“whoa there, sweetheart, d’ya really think you should be makin’ demands? where d’ya think ya are?”

The other didn't respond and glared down at the rock pillow.

“ya got a name, feather-butt?”

To Red’s surprise, a muffled snicker came out of the Fallen’s mouth. He stared back up at him, his expression surprisingly neutral and lacking the usual fear Red had expected to see. He was impressed.

“nice one. too bad my butt’s as bony as yours.” He paused and tried to shift his position, which only jostled his feathers and caused one to flutter onto the ground. “i go by sans.”

“red.”

Figuring that introductions are done, he placed the collar in front of Sans’s face and stepped back with a smirk.

“put it on.”

Sans made no movement to grab the offered object; in fact, he stared at it with open bemusement and barely suppressed disgust..

“c’mon, don’t make this difficult. ya think a fallen angel such as yerself is safe wandering around unclaimed?”

Sans’s eye lights blinked out, leaving black pits, and his permanent grin tightened. Soft rattles filled the room as Sans trembled. A tinge of pity peaked within Red’s soul, and he placed a hand on the other’s right shoulder. Sans’s white pinpricks reappeared, and he flinched away as if Red’s touch had burned him. Red let go and raised both of his arms in a placating manner.

“if ya dislike the design, i can get boss to make ‘nother nicer one for ya.”

It took another long minute before Sans nodded and mumbled something that Red couldn’t hear.

“what was that?”

“... c-can you p-put it on?” Sans didn’t look at him as he spoke.

Red’s mind stumbled into a halt as he processed the small skeleton’s words. Then his razor-sharp teeth cracked to a full grin.

“sure, sweetheart.”

And as Red slid the collar around Sans’s unmarred neck, he pressed his teeth softly against Sans’s left cheek.

Perhaps this fallen angel will brighten up his boring existence.

**Notes for the Chapter:**

> This will become a longer fic. Day 22 was originally be glory hole but this plot bunny would simply not evade me until I wrote about it, so here it is. After I finish Cursed Obedience, I plan to make this drabble into a full fic. And when it does, the full pairing will be SpicyKustard (UF Pap x UF Sans x UT Sans).


	23. Shibari (Alphyne)

**Summary for the Chapter:**

> Alphys expresses her love to Undyne through ropes.

**Notes for the Chapter:**

> **additional warnings: nipple play, scissoring**

“I-it’s not too t-tight?” Alphys asked nervously as she completed the box arm tie behind Undyne’s back. 

Her girlfriend, who was kneeling on her calves, fidgeted. She wore a simple, black tank top and matching-colored panties. 

“It feels nice, Alphs. Make it tighter! I can take it!” Undyne gave a wide, challenging grin.

“We’ll see. S-safety f-first.” 

Alphys brought the three-stranded jute rope around Undyne, fitting it securely above her breasts before bringing it around her back. While embracing Undyne within her arms, Alphys wrapped the ties below her breasts. Undyne inhaled sharply when Alphys pulled the ropes taut. She secured the rope in an elaborate knot behind Undyne. Before she broke the hug, Alphys swept aside the captain’s crimson bangs and pressed her lips on Undyne’s forehead. 

“Oh man, that felt nice, Alphys. You should give more forehead kisses,” Undyne teased with a wink of her one eye.

“If you w-want me to, I would l-love to.”

Exhaling a deep breath, Alphys grabbed another set of jutes and began tying it around Undyne’s right ankle. Alphys then brought the rest of the rope around her upper-calf and lower thigh, and bound them flush against each other. Undyne’s left leg received the same treatment. With each careful knot completed, her fish girlfriend’s breath quickened.

When Alphys finished, Undyne laid her back and bound wrists against a body pillow, the ropes forcing her legs wide opened. The black tang top did nothing to hide the fact that her nipples had become erect. Alphys paused to admire how wonderful Undyne looked, with her blue-skinned cheeks flushed pink from arousal. Heat pooled down to her own crotch. But she couldn’t relieve it yet. She still had a bit more to do.

“H-how’s it feel, Undyne?”

Undyne tested her bounds and purred, “Great!”

Alphys blushed scarlet, her soul thumping within her chest like a beating drum. She shook her head to clear her mind and seized the final set of ropes. Her fingers ran through them as she carefully studied Undyne’s splayed out, clothed pussy. The fish monster shifted restlessly.

“Everything alright there, Alph?”

“O-oh? Y-yes!”

Alphys approached Undyne with a sway to her hips. She slid the body pillow further back so she could sit behind Undyne, wrapping as much of her arms around the captain from behind as she could. As she did so, she coiled one end of the rope around her waist and tied it into a knot above Undyne’s bellybutton. Alphys then looped the remainder over Undyne’s slit and under her ass to tug the cord back up and around her waist, wrenching a sharp gasp from Undyne. 

Feeling rather bold at having her lover at her mercy, Alphys turned Undyne's head to her by her chin and kissed her. It didn’t take long for their tongues to join together. While their appendages danced around each other, Alphys’s other hand crept up to pinch at Undyne’s erect nipple. A muffled moan escaped from Undyne’s mouth. She squirmed against the wonderfully tight bonds, filled with Alphys’s adoring love, and ground her pussy against the rope pressing into her lips. 

They finally pulled, a string of spittle connecting their panting mouths. It eventually broke apart. Alphys continued to twirl Undyne’s perked nub in between her thumb and forefinger. 

“F-fuck, Alphys! Th-that feels, ah, SO GOOD!” Undyne moaned.

Alphys could only smile as she watched her girlfriend come apart by her hands, by her work. She gripped the pillow behind her and used it to prop Undyne’s back against it again. 

“This isn’t, um, straining your wrists and arm, is it?” Alphys fidgeted with the hem of her nightgown.

“Nope, feels fine!”

Alphys hummed as she straddled Undyne’s waist, interlocking her own legs with Undyne's bound ones. She sank down on Undyne’s crotch, forcing the rope down into her vagina. Alphys set the pace, rutting her own wet and uncovered cunt against the twine. 

“Alphys!” Undyne cried as Alphys increased the pace.

Their lewd cries and wet squelch of their fornication filled the room. Alphys reached between them to jerk the rope, making it rub against both their clit. Moments later, they came simultaneously while calling out each other’s name. Once they calmed down from the afterglow, Alphys untangled all the knots and ties. She sighed in bliss as she laid on top of her freed lover.

“Thanks for letting me do th-this, Undyne.”

“This was great Alph. It’s always relaxing being tied like this. And it’s like I can feel your emotions through the ropes! It’s SO COOL! We should do it again. Except next time, you should be in my position, fuhuhuhu.”

“Yeah, I would love to.”


	24. Fisting (US Papyrus x Muffet)

**Summary for the Chapter:**

> Papyrus pleasures Muffet to pay his debt.

**Notes for the Chapter:**

> **additional warnings: vaginal fingering, penetration, light bondage**

Feeling bored with Sans currently out having a sleepover at Alphys’s, Papyrus took a quick stroll to Muffet’s Parlor. A soft jingle rang out as the door opened and closed. It was a quaint little cafe decorated in red, purple and white colors. The dark-haired spider lady waved one of her arms in greeting.

“Ahuhuhu welcome, deary.” She winked with two of her eyes.

“yo, muffet,” Papyrus called with a languid wave. He sauntered over and took a seat at her counter. 

“The usual, I presume, deary?”

“you know it.” Papyrus gave a precocious wink. 

Muffet giggled and slid a glass of spider cider spiked with honey to Papyrus, who stopped the drink with his index finger and thumb. A sip later, warmth flooded his bones. He sighed with contentment. He spent the next few hours lounging around the cafe, sipping his drink and nibbling on a few of Muffet’s spider donuts. They were crunchy. 

At half past ten, once all the patrons left save for Papyrus, the eight-legged monster swept the floor and wiped the tables down. Papyrus helped by using magic to move the plates, cups and glasses into the sink. Once completed, Muffet directed him with a coy glance and descended the stairs one step at a time. Papyrus followed immediately after, his magic already strumming with excitement.

They had a casual, friends-with-benefits sort of deal. Papyrus had proposed it as a way to pay back all his debt to her. It was a nice arrangement, having sex with _no strings attached_ , heh.

Muffet’s basement bedroom was decorated in the same color scheme as her parlor, with silk purple sheets (created by Muffet herself), white drapes and a red rug. As Papyrus was admiring the decor, Muffet yanked him over to her bed and, with surprising amount of strength for a dainty spider, forced his back against the bed. Muffet straddled Papyrus’s lower spine with her lowest two legs, and stripted off Papyrus’s orange hoodie and undershirt. Six arms danced across and down Papyrus’s ribcage. His breath hitched.

At some point during Muffet’s ministrations, Papyrus trailed his phalanges down Muffet’s thin, black legs. Shivers wracked her frame. She then used her middle two appendages to peel off her dress shirt, pants and stockings. While doing so, Papyrus grabbed the tube of scented lubrication sitting on a nightstand and doused the oil over his hand.

With the barrier of clothing gone and his hands slick, Papyrus snuck two fingers into Muffet’s pussy. She clicked her tarsus and claws together in a frenzy. Papyrus pumped his fingers in and out of the wetting channel, and then stuck a third finger inside.Then another. And eventually his whole hand. Muffet ground down against his driving hand, throwing her head back and crying out in ecstasy. 

“Yes, dear~! Keeping going, ah~ just like that!”

Muffet’s tiny claws dug under the sensitive portions of Papyrus’s ribs and within the spaces between his vertebrae, causing pressure to coil within his pelvis. His magic morphed into lengthy, orange erection. 

Papyrus jabbed his hand into Muffet’s pussy, except for his thumb, which he used to rub her clit. He curled his fingers along the spider’s clenching walls. Muffet came with a loud cry. Papyrus withdrew his hand with a wet squelch. Not even a minute later, Muffet shifted up to hover her heat over his cock.

“wha-” 

Muffet impaled down on his length. Papyrus moaned and his arms scrambled for her hips. Before they did, silk shot out from the spinneret in Muffet’s butt and trapped Papyrus’s wrists to the headboard.

“Ah, ah. Allow me to lead, deary. Ahuhuhu.”

Muffet raised herself until her cunt was at the head of Papyrus’s dick and then plunged back down. He wailed. She set a rapid pace riding him, Papyrus trying to snap his hips to meet her movements. The pressure coiled within him snapped. Her walls tightened wonderfully against his length, tipping him over the edge. Cum shot out of his cock and filled Muffet’s channel.

The two of them laid on the bed for several minutes before the parlor owner extricated herself from him. The silk wrapped around his wrists loosened, allowing him to pull free. 

“Again next week?” Muffet asked with a click of her pincers. 

Papyrus pulled on his clothes and nodded.

“yep.”


	25. Boot Worship (MettaSans)

**Summary for the Chapter:**

> Sans pulls a prank that gets him in trouble with his boss.

**Notes for the Chapter:**

> **additional warnings: mild dubcon**

Sans stood hidden behind draping dark curtains, white pupils trained on the stage where his boss, Mettaton, currently sang and danced. He held a black boxed device with two buttons on it. When Mettaton was a step away from the trapdoor hidden in the floor, Sans pressed a red button. The door swung opened, causing Mettaton to trip over his two inch pink heels. The robot stumbled three steps and caught his bearing, but not before emitting a loud farting noise.

Dead silence filled the MTT Resort Auditorium; even a pin drop would be heard. One nervous chuckle broke out amidst the audience, followed by several others. Soon, laughter echoed throughout the entire amphitheater. 

Mettaton snapped his head to the back stage just as Sans vanished. Sans appeared in his assigned bedroom at the Royal Palace. Ever since Mettaton had taken over as king of the Underground - after the death of Asgore by the human kid - he and Papyrus stayed five nights a week there. It was mainly because Mettaton insisted they live with him since he and his brother had become his agents. It was a nice gig, giving Sans numerous opportunities to ogle at his secret, never-would-admit crush.

Sans knew he was going to get his comeuppance for messing with Mettaton’s show. He simply saw the perfect opportunity to pull off his whoopee cushion prank, and did it. Besides, Mettaton’s ego was larger than the entire Underground since he’d taken over, and the prank had been Sans’s way of deflating some of it. It also amused him when he messed with Mettaton; he made it practically an experiment to gauge how far he could push the other’s buttons.

Exactly an hour later, loud and furious banging came from the door of his room. Sans waited several seconds, and then slowly shuffled over to the door. As soon as he turned the knob, the door swung forcefully inward. He dodged just in time to avoid getting smacked by the wooden barrier.

“sup, metta? whaddya need?” Sans kept his voice casual.

With a sharp click of his heels, Mettaton rushed inside and slammed the door shut. He seized Sans by the collar of his shirt and lifted him into the air.

“Do not act coy with me, Sans! I know what you did! Your unfunny prank has ruined my first-class performance!” Mettaton snarled. “What do you have to say for yourself?!”

Sans shrugged, lifting up both of his arms in a noncommittal manner. 

“what’re ya gonna do ‘bout it? fire your best agent?” Sans had the nerve to wink his right eye.

A smirk curled onto Mettaton’s metal face. 

_Slam!_

Without warning, Sans found himself pinned against the wall with his wrists trapped on either side of his head by Mettaton’s extended arms. White hot pain exploded at his pelvis as Mettaton dug his pointed heels at his ischium, wringing a pained gasp from him.

“You sure are bold… Sansy.” Mettaton purred the last part near the side of his skull. “Do you find enjoyment in testing my patience? Perhaps I should give you a lesson, darling.”

Mettaton forced his heels further against his pelvis and scraped it up and down his coccyx. 

“gah!” 

The pain brought tears to the corner of his eye sockets. But as Mettaton’s harsh prodding continued, a heated tightness coiled around his pelvis. Before he knew it, his magic formed a hardened shaft, tenting his pants. It took the brunt of Mettaton’s boots.

Mettaton’s smirk widened.

“My, my, Sans. I never took you for a guy to get off on this,” Mettaton uttered as if he’d just won the lottery. 

The robot released Sans, who slipped onto the floor. Sans’s dick throbbed in need. His cheekbones flushed blue in shame and arousal. 

Why was he so turned on by this?

“Do you need some help?” Mettaton towered over his crumpled form. “I am willing to pay my employees in kind. But only if they follow. My. Rules.” Mettaton punctuated each word with a jab of his boot at Sans’s erection.

“ _c-cum_ on,” Sans quipped with a gasp. “h-help a guy out, it would be _boot_ iful, heh.”

Mettaton suddenly stamped his right boot centimeters from Sans’s face.

“Lick it!” he ordered. 

Sans stared.

“Kiss and lick my boots if you want any favors from me.”

After coming to the realization that he didn’t really have much dignity to lose, Sans got down on his hands and knees and peppered Mettaton’s hot-pink footwear with kisses and kitten licks. He started from the tip of toe, worked his way across to the heel, and then upwards to the calf portion. Blue saliva dripped down the right side. When Sans finished, he gazed up at Mettaton.

“Now do the other one.”

The heat within his face burned as intense as the lavas of Hotland as Sans swiped his blue tongue down the show robot’s left boot. Once he reached the tip, Mettaton knocked Sans onto his back. Sans used his palms to sit up. 

“Wonderful work.” Mettaton hummed. “Allow me to repay you for a job well done, darling.”

The king tilted his shoes in a way that slipped Sans’s dick in the crevice between the heel and ball. Mettaton shifted slowly up and down. Sans panted and threw his head back. Mettaton quickened the pace, adding a few jerky jabs at odd intervals. The friction from the clothes and the roughness had Sans coming within a minute. 

Sans barely had time to come down from his high before he was lifted back up into the air and thrown onto the bed.

“Don't think we’re done yet, darling.”

Mettaton's eyes sparkled with excitement and hunger.


	26. Mirror Sex and Stockings (Swapfell Sans x Swapfell Papyrus)

**Summary for the Chapter:**

> Sans wants to show Papyrus just how beautiful he is by having a room filled with mirrors

**Notes for the Chapter:**

> **Additional warnings: incest, praise kink, fucking someone with a riding crop, restraints, chains, ecto-vagina and ecto-penis**

Papyrus quaked at the full-length mirror standing at the foot of their shared bed. A similarly large mirror had been installed on top of the ceiling, allowing a perfect reflection of their queen-sized bed. Moveable mirrors also sat on either side of the bed at approximately two feet away. Sans had ordered their playroom to be designed in this manner after discovering Papyrus’s poor self-image and monumental self-hatred.

Glancing furtively at mirror and seeing the scars, chips and breaks littered on his naked body, Papyrus didn’t know what Sans saw in him. He was ugly, disfigured… disgusting. Especially compared to his magnificent Lord. 

Papyrus was lying eagle-spread on the bed with his wrists shackled to each bedpost on either side of the headboard. His ankles were similarly restrained. Bound as he was and with the room filled with mirrors, there was no way for Papyrus to look away, no way for him to not see himself. But at least he could still close his eyes.

“YOU ARE STILL UNCOMFORTABLE,” Sans’s sharp voice rang out in the silence.

Sans took several steps forward until he was hunched over Papyrus. He had a leather riding crop in his left hand. His ribs were bare, and the only form of clothing on him were thigh-high stockings, which he had to tape to his femurs so they wouldn’t slip. 

“PERHAPS WE SHOULD BEGIN. I, THE MAGNIFICENT AND MERCILESS SANS, WILL SHOW YOU JUST HOW WONDERFUL YOU ARE! DO NOT CLOSE YOUR EYES!”

Papyrus’s eye sockets snapped opened. 

“FORM A PUSSY!” His brother commanded.

“yes, m’lord.”

Like a trained dog, the orange magic at Papyrus’s pelvis coalesced into a damp slit. A smirk crawled up on Sans’s skull, and he expertly brushed the riding crop along Papyrus’s lips. Fluid began to coat his vaginal walls. Papyrus shivered, catching sight of it in the ceiling mirror. His eye sockets lidded.

“DO I HAVE TO FORCE YOUR SOCKETS OPENED? I SAID DO NOT CLOSE THEM!” The order was followed by a sharp jab of the crop into his pussy.

“ah! y-yes, m’lord,” Papyrus gasped.

He squirmed against his bonds, filling the room with the clattering of chains, as Sans fucked him with the leather whip, prodding the riding instrument deeper into his channel and jerking it relentlessly against the walls of his cunt. His skull was a deep orange, and he could see the arousal within his own face. When he turned his head away from the ceiling, he still saw himself in the mirror standing beside the bed.

“EVERY SCAR ON YOUR BODY DEFINES YOU, PAPYRUS,” Sans praised. “YOU ARE BEAUTIFUL JUST THE WAY YOU ARE.”

While Sans’s left hand continued to work the riding crop, his right ran down each and every chip, mark, and deformity on Papyrus’s naked frame. Papyrus watched as thin phalanges caressed his marred ribs, sternum and vertebrae. A deep groan fled his mouth when the crop dug against his clit. His walls clenched around the gyrating leather. Papyrus saw himself arch his spine, his face in an expression of utter bliss, as he came with a cry.

Sans continued his ministrations at Papyrus’s cunt as he rode through his orgasm, and the overstimulation brought tears to his eyes. When the crop was finally removed, Sans climbed onto the bed and crouched in between his spread legs.

“DO YOU UNDERSTAND?’

“y-yes, m’lord.”

“THEN REPEAT WHAT I HAD SAID.”

“my scars define me. i am beautiful just the way i am.”

Sans hummed. A purple glow illuminated the room when his girthy cock blinked into existence. Papyrus watched with lustful eye lights as Sans pumped his length several times. Purple pre-cum dripped out of the head. 

In one swift movement, Sans lined the head of his dick to Papyrus’s slit and drove directly to the hilt. They both moaned in unison. Sans set a rapid and rough pace. Papyrus could see his brother’s violet cock plunged in and out of his walls. 

It was beautiful, how their two magical colors - orange and purple - mingled together. 

“YOU ARE GREAT, PAPYRUS. YOU ARE ALWAYS THERE FOR ME, ALWAYS THERE TO PROTECT ME.” Sans’s cheeks flushed. “I DO NOT GIVE PRAISE MUCH, BUT FOR THIS ONE TIME, I WILL TELL YOU EVERYTHING!”

And he did. Sans’s words had Papyrus’s soul fluttering within his chest like butterflies. Warmth pooled at his groin, causing his walls to throb. He saw himself arch his spine as much as he could, and tried to meet his brother’s rough thrusts. When Sans, once more, grabbed the riding crop and twirled the leather portions against his engorged bud, his walls clenched against Sans’s length.  
“m’lord! sans!” Papyrus wailed, climaxing a second time that night. 

Sans soon followed after with a similar cry of his name, and collapsed on top of him. Despite his brother’s boisterous enthusiasm when it came to sex, his stamina wasn’t the greatest. After minutes of just the two of them breathing in synchrony, Sans finally released his limbs. They slipped under the covers and fell asleep within each other’s arms. 

He barely noticed the mirrors.

**Notes for the Chapter:**

> This is my first time writing the SF bros. I dunno if this fits their fanon characterization. Probably a bit too fluffy but whatevs.


	27. Temperature Play (Grillby x Papyrus)

**Summary for the Chapter:**

> Grillby uses a bit of his fire and a bit of snow to set Papyrus's bones alight and freeze them in sight.

**Notes for the Chapter:**

> **additional warnings: soul sex**

In the late after hours of his bar closing, a knock rang out. Grillby turned around from his shelves of drinks to face his front door. Another knock, more forceful and familiar, rang out. Grillby stepped out from behind the counter and treaded towards the wooden barrier. When he opened it, Papyrus stood in the doorway, threading his uncovered, bony hands tightly within each other. He was dressed in his orange bone-patterned pajamas. 

“IS IT TOO LATE?” He asked in his usual boisterous tone, though it sounded more hesitant than usual. 

Grillby stepped aside to allow Papyrus entrance. The tall skeleton bustled inside and closed the door behind him. As soon as he did, Papyrus strolled up to Grillby and gave him a light skeleton kiss on his flaming face. Orange dusted his skull. Grillby chuckled at the gesture, the sound akin to the crackling of firewood. 

“Why don’t you wait upstairs… while I prepare?”

“OF COURSE!” Papyrus beamed with excitement as he bounded up to Grillby’s bedroom. 

Their secret relationship was something Grillby took great pride in keeping. It all began one evening when Papyrus came over to pick up Sans after he’d drank one to many spiked ketchup bottles. It had been after closing, so he and Papyrus ended up chatting for a bit. Through their surprisingly civil conversation -- give how much Papyrus had disparaged his greasy food and establishment -- Grillby found himself drawn to the younger skeleton brother. Papyrus seemed to have a constant spark within him. Like his own undying flame of sorts.

After that night, they’d set up many more meetings, usually late in the evening after most of Snowdin fell silent with sleep. Sometimes they would chat; other times they would be more… intimate. Tonight was the later. 

Grillby went to the back of his kitchen, retrieved a black glove from one of his drawers, and slipped it on his right hand. He then opened his back door, which led to his half-snow-covered and half-coal-covered backyard. Using his gloved right hand, he filled a thermos with ice and snow. Once complete, he closed his door and ascended the stairs to his bedroom.

Papyrus sat on the bed with his back ramrod straight, his excited magic eluting out of him in waves. Grillby closed his bedroom door, set the thermos on his nightstand and stripped away his clothes. He then joined Papyrus on the bed. 

“WHAT ARE WE DOING TONIGHT, MY DEAR GRILLBY?” Papyrus deepened his voice for the last portion.

Grillby’s embers brightened as he gently pushed Papyrus to lie on his back. He carefully undid two of the buttons on Papyrus’s pajama shirt and slid his palm across the white bone. Papyrus gasped. 

“... How about we… change the temperature up a bit?” 

Fire continued to dance up Papyrus’s chest.

“WOWIE!! THAT FEELS GREAT!”

Three more undone buttons later, and Papyrus’s shirt was off. His pants followed soon after. As Grillby’s amorphous, fiery hand snaked within the spaces between each of Papyrus’s alabaster ribs, his right gloved one grabbed the thermos and popped off the lid. He scooped a handful of snow and showered the icy substance onto the skeleton’s pelvis.

Papyrus shuddered against the contrasting heat and cold. Grillby increased the temperature of the embers smoldering the underside of Papyrus’s ribs, some even brushing his clavicles. Meanwhile, he continued to drizzle more snow and ice on the younger monster’s lower half, including in between the spaces of his lower vertebrae. 

Papyrus moaned as his back arched from the bed, and his fingers clutched at the bedsheets beneath him. Grillby’s tongue, not dissimilar to hot, liquid wax, licked up along Papyrus’s sternum. The skeleton wailed, and a bright light filled the room. When Grillby looked up, he spotted a glowing, inverted heart hovering inches above Papyrus’s squirming form.

“Papyrus…” Grillby muttered. He raised both hands. “...may I?”

The lanky skeleton, whose face was dusted a bright orange and sockets were lidded with arousal, gave a desperate, “YES, PLEASE!”

Grillby cupped Papyrus’s soul within his two hands, one like the chill of Snowdin and the other like the warmth of Hotland. The heart-shaped organ dripped magic fluid, coating Grilly’s flames. He could sense all the unabashed love Papyrus had for him, his utter trust, setting Grillby’s own magic alight. 

Grillby pulled away and, with his right hand, seized the thermos to scatter some snow onto the surface of Papyrus’s soul -- the top side cold, while the bottom hot. 

“AH~! GRILLBY!”

Papyrus twisted against the bedsheets, tears springing to his eyes from the overwhelming contrast against the culmination of his entire being. Grillby’s own soul materialized within the air in front of his well-toned body. It fluttered into the hand holding Papyrus’s soul, their shared love transferring and melding together in harmony.

Grillby shifted over Papyrus’s prone form and lined his crotch along Papyrus’s bare pelvis. He ground down, jerking their souls together in his palms. Another wail escaped from Papyrus’s mouth. As Grillby thrusted against Papyrus, his fiery form licking against the other’s bones, he brought their two souls to his irregularly shaped mouth, and gently bit down on the tip of the heart.

The pleasure hitting the both of them was so great that they both climaxed, blanketing the room in an illuminating glare. In a flash, the two souls dimmed and returned to their rightful place. Grillby’s inferno of a body expanded and shrank from the post-orgasm bliss. Beneath him, Papyrus’s chest rose and fell rapidly.

“THAT WAS TRULY MAGNIFICENT! I, THE GREAT PAPYRUS, HAVE TO APPLAUD YOUR FINESSE! YOU REALLY LIT MY BONES ON FIRE! NYEH HEH HEH!”

Grillby turned bright yellow in response to the compliment. Papyrus grasped his right arm and slipped off the gloves. 

“I AM GLAD THE SNOW DID NOT HURT YOU! THANK YOU FOR THIS WONDERFUL TIME!”

Grillby crackled and popped. “It’s no problem… Papyrus. I am always here… for you when you need me.”

Papyrus beamed and pressed his teeth against Grillby’s face in a long, deep kiss. When they pulled away, Papyrus got up to grab his pajamas. He got dressed while Grillby laid in bed.

“UNTIL NEXT TIME, GRILLBY, MY SECRET FLAME! *WINK*!”

Papyrus opened the door and left. Grillby hummed as he planned their next meeting.


	28. Xenophilia (US Sans x lamia!SF Sans)

**Summary for the Chapter:**

> US Sans finds an injured lamia in Waterfall and decides to help it.

**Notes for the Chapter:**

> **additional warnings: uh interspecies sex... kinda, ecto-cock**

Sans was on his way home from training with Alphys when he spotted a crumpled form lying, partially hidden, in the marshy tall grass. As Sans crept closer, he saw that it was a fallen skeleton monster. Or partial skeleton monster. Their skull and upper torso were similar to his own, though fresh cuts, chips and fractures marred the monster’s ribs with one even running down the left side of their face. They also had jagged, shark-like teeth. 

Sans’s eyes widened as he caught sight of the translucent, purple, snake-like lower body. They were coiled in a tight ball. Violent tremors wracked the unconscious monster. Sans dashed towards them and lifted them into his arms. They were surprisingly light and only a tad bit smaller than himself. 

Once the half-skeleton, half-snake monster was secure in his arms, Sans rushed back home. Thankfully he wasn’t that far from the entrance of Snowdin from Waterfall. Out of all the times he carried healing items in his inventory, this had to be the one time that he forgot. When he got home, he found Papyrus passed out on the couch. Sans puffed out his cheekbones, ready to scold him for his laziness, but then remembered the injured monster in his arms.

Sans rushed up the stairs into his room, grabbing some bandages and healing ointment from the bathroom along the way. He formed a nest of blankets on his bed and laid the half-snake monster -- a lamia, he believe they were called -- onto it. He then began to treat the lamia’s wounds, covering the cuts with healing cream and then carefully wrapping them in clean bandages. 

Just as Sans finished, the monster opened their eyes. Brilliant, violet eye lights glared back at him, and before he could react, the lamia pounced at him. Sharp teeth sank into the bones of Sans’s right ulna, who just barely suppressed the astonished cry that threatened to break free from his mouth. There’s no doubt that Papyrus would not approve of his taking care of this snake monster, especially since they’d just hurt him.

“IT IS OKAY. I WILL NOT HURT YOU,” Sans cooed in the softest tone he could manage, which was, admittedly, still loud.

Sans held out his left hand to the snake. Their purple tail glistened as they twisted in the blanket nest. 

“RAZZ! I SHALL CALL YOU RAZZ!”

Sans received an angry hiss. Razz let go of his left arm and slithered under the bed. Disappointment flooded Sans’s soul, but he immediately brushed it aside. The poor monster probably hadn’t eaten in many days. 

After he dealt with his own injury, he rolled down the undersleeve of his battle body and bounded down the stairs and into the kitchen. He made sure to close the door to his room. 

It didn’t take him long to prepare five hot-cat (they’re actually water sausages) tacos - two for his new friend, two for his brother and one for himself. He set the taco down on the kitchen counter for when his brother woke up.

When Sans went back into his bedroom, he found his pillow utterly mawled. White feathers littered the bed while the pillowcase were ripped into three pieces, one of them still hanging from Razz’s mouth. Sans nearly dropped the tacos. He closed the door to his room and marched towards his bed.

“WHY DID YOU ATTACK MY PILLOW? WHAT DID IT EVER DO TO YOU?”

Razz turned to him and hissed. When he caught site of the tacos, however, he stopped and slithered over to him. Razz lunged at Sans, who dodged this time.

“IF I GIVE YOU THIS, YOU MUST STOPPING ACTING SO MEAN.”

Sans stared down at the lamia, not wanting to let this rude behavior slide. He could change Razz for the better. And sure enough, after several long minutes, Razz finally bowed their skull in a gesture of agreement. Both of them ate silently. 

Deciding that he should spend some time with Papyrus to limit any suspicion, he bid his snake friend a temporary good-bye, and left his room. Sans couldn't discern if the expression on Razz’s face as he left was one of sadness or exhaustion. 

When he came back up to his room at bedtime -- he’d forgone his bedtime story for this one time -- he found the monster coiled under his bed. 

During the middle of the night, Sans was pulled awake by something warm and fleshy brushing along his clothed pelvis, heat pooling there. His sockets blinked open to find Razz wrapping their tail over his pelvis. A surprised groan escaped his teeth as Razz rutted against the swirling magic forming around his pubis. The lamia’s cheeks were flushed a deep violet and their eyes were lidded with lust. A musty scent permeated his room.

“WHAT ARE FEELING COLD?” Sans asked.

Razz responded with more furious rutting. Their translucent tail burned like the lavas of Hotland. The needy chirps and cries eluting out of them stirred the magic at Sans’s pelvis to form into a hard cock.

“ARE YOU IN HEAT?” 

Razz responded with a harsher thrust. The snake’s cloaca was slick with secretory fluids. Sans shifted in his bed and slipped his star-decorated pajama pants halfway down his femurs.

“DO YOU WANT ME TO HELP YOU WITH YOUR HEAT? THE MAGNIFICENT SANS IS ALWAYS PLEASED TO OFFER HIS SERVICES!”

Razz nodded. Sans pumped his member a few times, slicking it with precum. Once he deemed it lubricated enough to not hurt his new friend, Sans lined up his thick, blue cock and plunged it inside Razz. Razz gave an ear-splitting hiss and sank their teeth into Sans’s left clavicle. Sans cried out at the searing pain, and then moaned as the pain and pleasure blended together to heightened the whole experience. 

Slowly, Sans pulled out and plowed back in, setting a rhythmic pace. Razz extricated their teeth from Sans’s bones, and rested their skull against Sans’s shoulders, their thin, forked tongue flickering at his bones. Sans giggled and increased his pace. He drew closer to his peak. Three more thrusts later, he spilled his seeds into the lamia. His phalanges stroked the tip of Razz’s tail, sending them over the edge.

The two of them stayed connected for a few minutes, riding out the blissful haze. Just as Sans was about to pull out, the door to his room swung opened to reveal Papyrus standing in the doorway.

“is that a frickin’ snake i hear?”


	29. Part I: Overstimulation (UF Sans x UT Papyrus)

**Summary for the Chapter:**

> While Sans and Edge are out, Papyrus decides that Red would be his First Time.

**Notes for the Chapter:**

> **Additional warnings: ecto-penis, ecto-vagina, both parts at once, penetrative sex**

Papyrus hummed a jolly tune as he prepared his renowned lasagna. His cooking skills have improved tremendously since they’ve reached the Surface. It helped that he worked part time at an Italian restaurant and that Undyne no longer was his sole cooking mentor. Just as he lined the casserole pan with marinara sauce, deft phalanges danced up his femurs. Papyrus squawked and spun around.

Behind him, face decorated with a mischievous and hungry grin, stood Red. Red, his brother and the rest of the Underfell monsters had all shown up when Frisk the human had broken the barrier. Pandemonium had broken out amongst the humans when two sets of monsters - with one more violent than the other - marched out of the Underground. Slowly, after two years of dissention, the humans had finally begun to accept both sets of monster. 

“whatcha makin’, sweetheart?”

Red stood on his tiptoes and leaned over the stove, his skull centimeters from Papyrus. Heat rushed to Papyrus’s face at their close proximity; he could sense the repressed magic eluding off of the shorter monster.

“I AM MAKING MY FAMOUS TOMATO LASAGNA BEFORE OUR BROTHERS GET HOME FROM THEIR ‘TRICK OR TREATING’.”

“lemme help ya.”

Considering Red was nearly as lazy as Sans, Papyrus was more than happy to oblige. Every now and then throughout their cooking session, Red would bump their hips together or stray hands would wander back and forth along his lower spine. Papyrus shivered at the feather-light caresses, his soul fluttering wildly and his magic churning within him in agitation. Red also gestured in a shamelessly lewd manner, oscillating his hands in the motion of mastubating.

By the time Papyrus had placed the lasagna inside the oven to cook, Red looked ready to jump his bones. Literally. 

“hey, sweetheart, since we’ve still got some time, want me t’ give ya a good time?” Red said in a husky voice and wiggled his bone brows suggestively. His face then became serious. “and i, uh, wanna be your first time, heh.” 

Papyrus flushed, and his soul gave a throb. He and Red had been official datemates for a year now. Though he recently also realized that he loved both Sans and Edge equally as much as Red, and they were all open towards loving each other. On one hand, Papyrus would prefer to wait for Edge and his brother’s return; but if Red could show him a good time, perhaps he could use that to pleasure Sans. The thought of wrecking his older sibling sent a rush of arousal to his groin.

“ALL RIGHT! LET’S DO IT! WE CAN USE MY COOL BEDROOM!”

They made it there in record time. Despite their excitement, they went slow, with Papyrus receiving a chaste skeleton kiss from the other. Papyrus was floating on clouds as Red deepened the kiss, swiping a ruby ectoplasmic tongue at his teeth. Papyrus granted him access. Closing his eyes in concentration, he summoned his own orange tongue.

The two appendages wrestled back and forth within their smooching teeth. Moans and pants filled the room. After a good minute, Red pulled his head back, breaking apart a trail of drool that connected their tongues. Papyrus’s magic stirred at his pelvis, waiting to form parts. 

“yer wonderful, sweet _cheeks_.” Red swayed his hips in gest. 

“NYEH HEH HEH!!! HOW KIND OF YOU. LET US MOVE TO MY COOL BED!”

Papyrus shifted over to sit on his bed, removing his battle body as he did so. He kept his black under garments on. Meanwhile, Red slipped out of his trademark black, leather jacket and discarded his track shorts. A girthy, red cock hung from Red’s pubis. Papyrus gaped at its thickness.

“don’t worry, papyrus, i’ll prepare ya good.” Red winked and shuffled over. “d’ya need help formin’ parts?”

Papyrus bobbed his skull enthusiastically and stripped off his leggings in a flourish. Unformed orange magic swirled at his pelvis. 

“how ‘bout we start simple?”

“SIMPLE? THE GREAT PAPYRUS WILL NOT STAND BY SIMPLE! HELP ME CREATE A DONG AS GREAT AS MY NAMESAKE!”

“heheh, alright. could ya spread yer legs a bit wider?”

Papyrus blushed as he shyly moved his femurs further apart. Using his index and middle finger, Red made circular motions at the magic in front of Papyrus’s pubic symphysis.

“now imagine the shape ya want.”

Slowly, the orange magic became an inch thick and grew longer. And longer. When the transformation was complete, Papyrus’s ecto-penis was almost doubled the length of Red’s. Said skeleton’s eye sockets widened to the size of saucers.

“geez, sweetheart, that’s one long, heh, _boner_.”

“NYAHHH!! DO NOT RUIN THIS WONDERFUL MOMENT WITH PUNS!” 

Red chuckled. He then seized the base of Papyrus’s cock with his lands and swiped his tongue at the tip, directing the magic to form a slit. Papyrus’s breath hitched.

“ready, big boy?”

After giving his consent, Red took the length into his mouth. Papyrus moaned at the warm, slick tightness around his dick. It was like nothing he’d ever experienced. It felt wonderful!

Red bobbed his head up and down Papyrus’s cock, teasing his slit every now and then. Pressure built up within Papyrus. Just as it felt ready to explode, Red withdrew from his member with a faint pop.

“not yet, papyrus. if ya really want the best experience, could ya form a pussy fer me? ‘bout right here?” Red pointed at the center of his own pelvic inlet. 

Papyrus closed his eyes and imagined the female sex parts he’d seen in those human anatomy books. A dripping mound formed.

“it’s beautiful, papyrus.”

The bed shifted, and Red climbed onto the bed to sit behind Papyrus. He wrapped his arms around Papyrus’s spine and dipped a phalange inside the slid, pumping it in and out a few times. Papyrus cried out in pleasure and ground his hips against Red’s finger. In slid a second digit. Red scissored the opening. Papyrus’s walls quivered and his still summoned dick twitched in need. The tightness mounting within Papyrus grew unbearable.

“PL-PLEASE, RED,” Papyrus stuttered with a groan.

“please what?” The smugness in Red’s tone set off a strange desire within Papyrus -- a desire to wipe that smugness clean. 

“P-PLEASE… PLEASE INSERT YOUR KEY INTO MY LOCK!”

Papyrus heard a cackle from Red. 

“alright, here i go.”

Papyrus raised his pelvis off the bed, allowing Red to plunge his cock into Papyrus’s tight pussy. In and out Red went. Papyrus attempted to meet his pace, which only caused the short skeleton to squeeze his ecto-penis. The sensations crashing within Papyrus quickly became overwhelming, clouding all of his senses into a haze. His walls began to clench around Red’s plowing length. When two phalanges pressed the bundle of nerves at the top of his slit, white filled his vision. He came with a wail. 

Three more thrusts from Red later, warm cum filled his vaginal cavity. Without even letting Papyrus ride out his first orgasm, Red pumped Papyrus’s dick. A second later, orange magic spewed from his cock. Tears sprang to his eyes from the overstimulation. He fell forward and laid on his bed, basking in the afterglow. His soul pulsed with love for Red, who snuggled within his arms. 

He couldn’t wait to pleasure Red the same way the older monster had for him. And to pay him back for that smug behavior earlier.

At some point in their comfortable silence, the door downstairs slammed open. Edge’s sharp voice rang out.

“RED, PAPYRUS, WE ARE HOME! WHERE THE HELL ARE YOU TWO?!”

As he and Red went downstairs, Papyrus decided to include Edge in the planning. Two Papyruses would be double the excitement and double the fun.


	30. Part II: Sex Toys (UT Sans x UF Papyrus)

**Summary for the Chapter:**

> Edge and Sans go trick or treating... with some _stimulations_.

**Notes for the Chapter:**

> **Additional warnings: vibrators, ecto-vagina, ecto-penis, orgasm denial**

It had been a little over two years since the Underfell universe merged with the Undertale one and all monsters had been freed from the Underground. Although Edge had been distrustful of humans initially, he no longer expected the worse out of them, which was why he, just like Papyrus, loved going out. This was especially the case for such an exciting holiday like Halloween.

Edge would never admit it to his lovers, but he loved Halloween and was excited to explore the tradition of “trick or treating”. It had taken some genius coercion on his part to convince his brother’s lazy counterpart and first boyfriend to come with him. He had given Sans the permission to dress up as whatever he wanted, and the bonehead decided to be a pumpkin. Not even a jack-o-lantern for the extra scare factor. A pumpkin was not scary at all!

Edge had also allowed Sans to do whatever he wanted with Edge for the night as the other major part of their agreement. Which was why, as Edge walked beside Sans in his elaborate vampire lord costume, shivers wracked his form every so often, and sweat dotted his forehead. Every step he took tested his ability to stifle his moans. 

The cause? A golfball-sized steel ball that has been inserted into his summoned ecto-vagina. And, hidden from the eyes of all the human and monster children and parents were two bone vibrators. One was located on his lower spine and the other on the posterior side of his sternum, the close proximity to his soul causing it to throb. Their low, barely audible hum echoed within Edge’s hearing, muffled under his costume. 

Every time they were at a house to pick up treats, Sans would decrease the vibrations, and then heightened them back up when they walked between neighborhoods. It drove Edge nearly insane. The ball hidden in his cunt didn't help matters, rolling against his walls 

“you doin’ ok there? we can stop this if ya want.”

“NO! THE GREAT AND TERRIBLE PAPYRUS IS A SKELETON OF HIS WORDS!” Edge proclaimed. “THIS IS NOTHING.”

“nothing, eh?” Sans’s grin widened.

Edge stifled his moans as the modified bone vibrators buzzed louder, stimulating his soul and vertebrae in ways he'd never imagined. Then the intensity died down again. Edge huffed with frustration and had to repress the urge to drag Sans into a back alley and fuck him with impunity. 

The two of them came upon a familiar house. They rang the doorbell and both Undyne and Alphys greeted them. They were both dressed as characters from that magical girl anime with the bizarre art style, and one - the yellow-clad girl Edge remembered - had her head bitten off by a “witch” or whatever. Alphys dressed up as the blue one with fake swords hanging at her waist, and Undyne was the red one that wielded a spear - she used her own.

“H-hey, guys! N-nice costumes!” Alphys greeted. 

Undyne inspected each of them. She pointed a finger at Edge, “A vampire and…” she raised an eyebrow as she fell upon Sans’s costume. “A pumpkin? For what purpose?”

“cause i’m edge’s _pumpkin_.” Sans had the nerve to give a left-eyed wink. 

Edge flushed with embarrassment, and his soul did somersaults within his ribs. 

“Did you seriously dress up in that just to make a pun? What a nerd!” The fish-monster snickered. She grabbed a fist-full of candy and poured it in each of their baskets. 

“so _water_ you gals up to?” Sans asked. 

“We’re going to Mettaton’s party!” Undyne replied, ignoring his pun.

Edge shuddered violently and gasped at the sudden increase cadence of the vibrators, making him weak in the knees. He glared at Sans, who smirked knowingly. Alphys’s beady eyes widened at his response, recognition dawning on her face. Her hands scrambled to cover her mouth. Thankfully, she remained silent.

When they left Alphys and Undyne’s home, Edge was already plotting his revenge against the smaller skeleton. Sans had lowered the intensity back to its lowest setting. Again. He discreetly attempted to squeeze his legs together to get more stimulation from his quivering pussy. 

They were just about finished with the third neighborhood when Edge lowered his head to Sans’s height and hissed quietly,” IF YOU DO NOT FUCK ME THIS INSTANT, I WILL RELIEVE IT MYSELF!”

Sans grinned and offered a hand. “alright, bud, let’s get outta here.”

As soon as Edge grabbed his hand, the vibrations roared back to life. A moan finally ripped out of his mouth, though it went unheard as the two of them vanished. They reappeared in Sans’s workshop located at the back of their shared house. A wave of dizziness crashed into Edge, and he lowered himself onto the floor with some help from Sans.

Normally, he'd be disgusted at having sex in such a dusty place, but he had grown desperate from being dragged on the brink of release. He unclipped his red and black cape, laying it onto the ground as a makeshift sheet, slipped off his fancy pants, and sat down with his legs spread. His engorged mound glistened.

“WILL YOU HURRY IT UP?!” he urged.

“what’s the rush?”

“WE ARE TO MEET OUR BROTHERS SOON, AND I WANT RELEASE AT LEAST ONCE BEFORE THEN!” Edge huffed.

“ok.”

Sans shimmied out of his hideous, green shorts but kept the main part of the pumpkin costume on. His blue erection sprang free. He stroked it back and forth three times to lubricate it.

“ready for my _gourd_ to fill ya?” Sans wiggled his bone brows in jest. 

"GET ON WITH IT!"

Sans lined himself up against Edge’s dripping slit and slipped in with the metal ball still inside. The stretch was delicious, and Edge keened.

Sans set a slow pace but increased the ferocity of the vibrators attached to Edge's spine and posterior sternum. Edge cried out at the sensations. He closed his eyes and gyrated his hips upward to meet Sans’s thrusts. Sans’s thick cock shifted the sphere trapped within his cunt. It rolled against his clenching walls. Phalanges played with his clit at the same time the vibrations hit their maximum intensity. 

“AHHH! SANSSSS~!” Edge cried. His walls clenched tightly around Sans’s length as he climaxed. The small skeleton followed immediately after. 

Stars dotted his vision from the intensity of the orgasm. When Sans pulled out, the ball slid out with a wet squelch. Edge shivered. Sans whispered praises to him as he removed the two bone vibrators, his words wrapping around him like a warm blanket. Edge sighed, eye lights gazing at Sans with appreciation and love. He definitely couldn’t allow all the other’s teasing to slide by without some payback. 

“ya ready to head home to our bros?”

“MORE THAN EVER!”

Edge donned his pants, smoothing out the wrinkles. He needed to speak with Papyrus; they had some planning to do.


	31. Part III: Special Foursome Combo (UF Papyrus x UF Sans x UT Sans x UT Papyrus

**Summary for the Chapter:**

> Papyrus and Edge get to have their fun with Sans and Red

**Notes for the Chapter:**

> So sorry for the delay. I just had to take a short break from this, one, due to difficulty starting this, and two, it just wasn't coming out the way I wanted. In the end, I'm ok with what I came up with. Think of this as an appetizer for when I write this pairing again in one of my fics.  
> Also, --- denotes change in POV. 
> 
> **additional warnings: foursome, tentacles, tentacle bondage, multiple penetration, orgasm delay/denial, ecto-parts (all), oral, possibly some others, etc.**

A week after Halloween, Red and Sans came home in the evening from Grillby’s to a house blanketed in darkness. Red flicked on the light only to find the living room in complete disarray with clothes and socks thrown everywhere -- at least, more so than usual. His soul pounded against his ribs as he and Sans searched the first floor of the house, finding it completely empty. Both their brothers should’ve been home, having their cooking session together.

Did something happen to them? The thought sent a chill throughout Red’s entire being.

“maybe they’re upstairs. let’s check their rooms.” Despite the calmness in Sans’s voice, the sweat beading his forehead and the way his fingers clenched into tight fists gave away his rising panic. 

They both vanished from where they stood. As soon as Red appeared in his brother’s room, something red, slick and warm wrapped around each of his limbs and hoisted him into the air. The ones around his ankles pulled his legs apart. An additional one wound around his lower spine. Red yelped and struggled against the appendages.

“red?!” he heard Sans’s concerned yell echoed through the walls of the adjacent room.

The door swung open to reveal the short, blue-clad skeleton. As soon as Sans entered, several translucent, orange tentacles shot towards him. One twisted around his middle and lifted him into the air. He floundered, causing another to snake around his arms and bind them together above his head. The final two, similarly to Red, coiled around each of his ankles and forced his legs apart. His fuzzy pink slippers slid off his sock-covered feet. 

“what the fuck?!” Red roared. 

“LANGUAGE, RED!” Papyrus’s familiar, shrill voice scolded.

“bro?” Sans asked, his white pupils darting around the dark room.

All of a sudden, light flooded the area, revealing Edge and Papyrus standing side by side. Both of them wore black, form-fitting leather. The attire only left their pelvises exposed.

“NYEH HEH! YOU BOTH HAVE FALLEN INTO THE TRAP CREATED BY THE GREAT PAPYRUSES!” Edge announced. He puffed out his chest, and his expression was entirely too smug for Red’s liking, though he couldn't deny how sexy his brother looked. “NOW WHAT SHOULD WE DO WITH YOU? ANY SUGGESTIONS, PAPYRUS?”

From his brother’s hungry gaze, heated magic pooled at Red’s pelvis, emitting a ruby glow through his shorts. They were promptly torn off. Red yelped and squirmed against the tentacles, which only led to them pulling his limbs outward until he was eagle-spread in the air. Sans’s shorts also joined his on the floor.

“BEFORE WE MOVE FORWARD, HOWEVER, IF EITHER OF YOU BECOME UNCOMFORTABLE WITH ANY OF THIS, PLEASE USE YOUR SAFEWORD OR SAFE ACTION!” Papyrus declared. 

“INDEED,” Edge conceded. “YOU SHOULD NOT FEEL OBLIGATED TO CONTINUE IF IT GETS TOO MUCH, IS THAT CLEAR?”

Red knew that was directed more at Sans than him; he had a tendency forgo his own comfort for the sake of the rest of them. They both nodded and gave the go ahead. 

A red tentacle grazed the magic pooling at his pelvis, forming it into a girthy, red shaft. The appendage pumped his cock while another slithered up his spine and into his ribcage. Red groaned and bucked his hips forward, hoping to get some more stimulation.

A sudden gagging sound had his skull snapping to the side just in time to see an orange tendril slide into Sans’s jaw, and begin pushing itself deeper inside him. Dribbles of saliva trickled out of the corners of Sans’s mouth. The sight of the cyan blush on Sans’s cheeks, along with his lidded gaze and the stifled noises issuing from him, shot straight to Red’s dick, making it twitch with arousal. His brother’s tentacle responded with a harsh squeeze of his cock, followed by the tentacle curling around the base. Red saw stars.

“PAPYRUS, WHY DON’T WE PUT ON A SHOW FOR OUR WONDERFUL BROTHERS! IT’S THE MOST WE CAN DO AFTER THE CONSTANT TEASING THEY GAVE US,” Edge sneered with a downright sinister smirk. 

“YES!”

Papyrus pressed his teeth against Edge’s with a sharp _clack_. A second later, their tongues materialized and entwined together, undulating back and forth between their opened mandibles like a dance. Edge’s gloved phalanges ghosted down the back of Papyrus’s spine and halted at the back of his naked pelvis. They caressed Papyrus’s lower spine and back pelvis. Meanwhile, Papyrus’s own hands rubbed the insides of Edge’s ribs. 

Red panted at the sight of his brother and his first boyfriend making out in front of him. God was it hot as hell. As he watched, his brother’s tentacles teased him to the brink of release yet the one tendril coiled around the base of his cock prevented his release. The mounting pressure within him was becoming unbearable, and he couldn’t even come given his _tight_ position. He gave a pitiful whine, which was ignored by the two smooching skeletons. 

\---

Sans wasn’t faring much better, trapped within a haze of his brother’s soothing, gentle magic. The slick appendage lodged within his mouth moved at a snail’s pace deeper and deeper down his conjured throat, accentuating every pulse and shift within its surface. At some point in midst of his brother and Edge’s show, the tentacle had crawled through his throat, his ribcage, down along his spine until it reached his pubic symphysis. Once there, it left no parts of Sans’s pelvis untouched. Muted cries of pleasure escaped from him as the tendril stroked at his most sensitive areas -- his coccyx, sacrum and pubis. But the pace was simply too slow! He squirmed within his bonds, though his brother did not let up the tentacles’ tight grip.

It was tortuous for both Sans and Red, especially as Papyrus and Edge rutted their pelvises together while two thick coils of magic -- one red, one orange and both with a penis-like head -- waved around each other. Their lewd display made the teasing even worse. 

“b-boss, stop the teasing,” Red whimpered. “i can’t take it no more!” Sans gave a muffled hum of agreement. 

Papyrus and Edge finally broke apart, both of them leering at Red and Sans through lidded eye sockets. 

“WHAT DO YOU THINK, EDGE? PERHAPS WE SHOULD HAVE MERCY ON OUR BROTHERS,” Papyrus suggested.

For another minute, Edge’s gaze lingered on Red and Sans each. Then, the scarlet appendages around Red laid him face up and splayed out on the large bed. The tendril impaled through Sans’s petite body pulled out of his mouth, freeing his cries and moans. The ones around his arms loosened their grip. Once freed, Papyrus shifted him on all fours on the bed over Red’s prone, eagle-spread body with his face inches from his counterpart’s dick. With the thick tentacle that had been in his pelvis finally gone, Sans’s magic took shape of a dripping mound. Red’s exhaling breath blew over his slit, wracking Sans with full-body tremors. 

“YOU TWO SEEMED TO HAVE ENJOYED OUR SHOW. WHY DON’T YOU RETURN THE FAVOR?” Edge proposed. 

Sans didn’t need to be told twice as he went down on Red, deep-throating his cock; Papyrus’s tentacle had prepared him well. 

“sans, ah~!” Red groaned.

A second later, Sans jolted and gave a muffled keen when a tongue darted into his slit, swiping back and forth within his soaked walls. Sans swallowed around Red’s ecto-penis, and his own muscle licked along the bottom as he bobbed his head. His hips jerked down on Red’s face. 

Just as he neared his peak, and began to sense the swell of Red’s member, Edge ordered, “STOP!”

Papyrus placed his hands on either side of Sans's skull and guided his head off of Red’s length. Sans whined as Red’s tongue withdrew from his throbbing pussy.

“p-please,” he begged in a daze. 

“PLEASE WHAT?” Edge’s asked in a smug tone.

“just fuck us already!”

“LANGUAGE, AGAIN, RED!” Papyrus admonished, and then pressed his teeth against Sans’s. 

From his periphery, Sans saw his brother stroke Red’s member, who howled with pleasure. It was swiftly silenced, likely by Edge’s mouth. As Sans kissed Papyrus, his and Edge’s tendrils writhed around him and Red.

Without warning, two thick appendages invaded his pussy. His surprised wail was swallowed by Papyrus’s tongue. One red and one orange tentacle plowed in and out of him in an alternating fashion. Edge’s second tendril entered Red’s conjured asshole, while Papyrus continued to pump his cock. 

Abruptly, Sans’s kiss with Papyrus was broken apart after the latter shouted a shrill, “WOWIEEEE!”

The last of Edge’s tentacle shot up through Papyrus’s open pubis and gripped his summoned soul. Papyrus responded by giving Edge the same treatment. Wet squelching, cries, and moans filled the room with a litany of their growing pleasure. 

Red came first, painting Sans’s face with his crimson release. Sans followed immediately after, his walls clenching around Edge and Papyrus’s magical extensions. Papyrus’s climax engulfed the room, briefly, in an orange light, as spurts of his cum shot into Sans. Edge orgasmed last, blowing his load into Sans and Red. 

Sans’s arms gave way, and he face-planted into the bed, smearing the sheets with red and orange semen. Both he and Red were lifted up from their positions as Edge and Papyrus joined them onto the bed. All four of the laid there, basking in the pleasant afterglow. 

Just as he sensed the others beginning to drift off, Sans quipped, “welp, we gotta do that that again sometime. i give that a _tenta_ -outa-ten.”

It was met with a low chuckle and two loud cries of false anger.

**Notes for the Chapter:**

> And with this, Kinktober 2017 is finally done (after going over by more than half a month.... oops). Anyway, thanks to all those who kept up with my weird drabbles and especially those who commented. Love ya. *mwah* :]

**Author's Note:**

> Feel free to visit me at [knowmeknot101.tumblr.com](http://knowmeknot101.tumblr.com) (NSFW).


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